Are the other playable characters alternate personalities? If not, are they related to Isaac? Is ??? one of them?
Is Mom a religious zealot, just insane, or both? Did she go insane from religion, raising Isaac, or her husband leaving them?
Is God evil or good in this game? Did He have Mom sacrifice Isaac for fun, as a test, or because he was the Anti Christ? Did He even ask her to do it or was she just imagining things? What is His relation to the Angels?
Is Satan trying to protect Isaac or awaken him as the Anti Christ? Does he just see Isaac as a customer and tries to get more payment in the Sheol path? How is he related to Mega Satan? Then there's the signs that he may even represent Isaac's Dad in some way.
Is the Lamb supposed to be a demonic Jesus? A representation of whatever Mom "should" have sacrificed? Some other, skeletal, horned version of Isaac himself? Or just some other demon monster? Its general placement as the boss of a location accessed after Sheol is beaten and Satan himself is killed raise a lot of questions, especially seeing as it is the "negative counterpart" to ???.
Did Isaac's Dad leave because he was a Jerkass, didn't feel like he could be a good family man, or to get away from his mentally unstable wife, who may have had several miscarriages?
Is the ending where Isaac turns into a demon good or bad? Is Isaac finally happy?
While the final ending provides some answers, it does raise its own questions. To what extent did Mom abuse Isaac, if at all? While her trying to kill him is a hallucination, the abuse implications in many items is hard to ignore. Why did Isaac's parents split and whose fault is it truly?
Mom's Heart/It Lives will rarely pose a serious threat to anyone who is good enough to reach it. It is considerably more of a challenge in Rebirth, however.
The red champion version of Mom looks impressive, but is actually far easier to beat due to her greater attack speed and lack of Mook Maker abilities. Players can just dodge the telegraphed foot attack and retaliate, occasionally dodging a bullet spread from her eye. It can be troublesome if you have one of the Fetus items, however, as you have to time them very carefully to land a hit and thus the fight drags out for much longer.
Satan in Rebirth. While his fellow Final Bosses received new tricks which generally made them much more impressive than they were in the original game, Satan stayed more or less the same, with only a couple of new attacks added in only one of his phases, which are quite similar to the attacks he already had. Add the increased potential for powerful item combinations, and he just Can't Catch Up.
Ultra Greed in Afterbirth is undeniably a fun battle, and it does take a while to win thanks to his scaled health gimmick. That said, given how easy it is to collect powerful items over the course of the run, coupled with the fact that Ultra Greed's attacks are telegraphed well in advance, he'll only pose a real challenge to characters with low health (i.e. the Lost) or those with low speed attacks. A patch buffed the health of his giant coins, making them more likely to survive the player's attacks, which means he gets to summon more mooks and recover more health (not to mention the bombs, though those are the easiest to dodge). He also Turns Red as his health drops, making the fight much more challenging. Greedier Mode in Afterbirth Plus fixes this further by giving Ultra Greed a second phase, in which he throws explosive coins all over the place while leaping to cause rock shockwaves and firing brimstone lasers out of the golden doors. A much faster-paced and hectic battle... that comes with its own weakness — as most of Ultra Greedier's attacks are explosive-based, the Pyromaniac and Host Hat items rocket him back into Anticlimax.
Delirium zig-zags on this. Against most characters, Delirium is pretty easy to beat as long as you have good damage and a fair amount of spare health. With certain combos, he can be killed faster than Mega Satan. Against the Glass Cannon characters like Keeper and the Lost, his constant teleporting (frequently into you for unavoidable damage) and Bullet Hell can make the fight almost a Luck-Based Mission.
Edmund admitted that The Lost was infamously too hard to play, and he has received a major buff in Afterbirth: he now has spectral tears, letting him fire through obstacles, and he starts with the D4, allowing him to reroll all his items in the hopes of getting better ones. A later patch buffed him even further: Holy Mantle is now an unlockable starting item for him, which many players consider to be THE most valuable item to get as the Lost, as it turns him into a two-hit wonder rather than one-hit. Although this clashes with the D4 if you have both, since starting with one of the most powerful items for the Lost means there are very few rolls you could get that would overall improve your loadout. Additionally, the Missing Poster Trinket now turns your character into The Lost if you die while it's equipped (after unlocking The Lost). This basically means you don't have to start a game as The Lost in order to unlock his stuff.
After some rather major internet outrage accusing Edmund of not caring about the fanbase and "throwing a temper tantrum" due to a patch adding extra items in that were promised to be put in the game in the first place, Edmund made this post, elaborating that the items weren't originally in the game due to an unexpected glitch, and he meant no ill-will towards anyone in the community.
The AfterbirthAlternate Reality Game was an example of this. In Rebirth, Edmund wanted the community to work together to unlock something in the game, but in the end, it was data-mined. In Afterbirth, the unlockable content wasn't even patched in until the game was finished.
After some backlash concerning nerfing the Stopwatch, Edmund tweeted asking the community what items they would like to see buffed. As of December 6th, a patch buffed several bad items (for example, the Scissors are now a two room charge, the Friendly Ball is now a three room charge, and the most important of all, the Stopwatch is no longer a Special Item, and activates when the Holy Mantle is triggered), fixed several bugs, and finally reworked sacrifice rooms.
As stated in Broken Base, Afterbirth+ as a whole was initially released to mixed reactions, particularly due to the difficulty spikes that bordered on just plain unfair at times. However, Edmund listened very closely to fan feedback over the next two months and tweaked the game accordingly, removing much of the Fake Difficulty and buffing underwhelming items. These tweaks have been very well-received by the community, and now Afterbirth+ is largely considered a good follow-up to Afterbirth.
The second Booster Pack for Afterbirth+ buffs Angel Rooms, with them now giving items more frequently and being able to spawn with multiple items which you would choose between.
The fifth and final Booster Pack was originally planned for release in late 2017, but was subject to a long Schedule Slip that delayed it until April 30, 2018. In addition to a new character and new items, the final Booster Pack included a large amount of quality of life fixes to improve the game, the sheer amount of which easily justified the Booster Pack's long delay, and as such it is widely considered by the community to be the best yet.
Loki, an always-smiling demonic baby, is quite preferred over Monstro II as the boss of the fifth floor. They even call him "Mr. Cool" in the credits.
Satan, boss of Sheol, is the most complex boss fight in the original game and is the only boss to have multiple complete health bars. Before he even lets you fight him, he sends out one of The Fallen at you, and once you beat him, he breaks out of the statue and goes berserk, using updated versions of The Fallen's attacks. And after you beat him... he gets right back up, flies offscreen, and uses Mom's battle strategy as the fight becomes more fast-paced with him constantly stomping on the floor. After you beat him here, he finally falls and gives you Ending 11.
Rebirth naturally tops Satan with Mega Satan, who combines Giant Hands of Doom, mixes in minor elements of Bullet Hell, and summons at least thirteen Degraded Bosses with a grand total of eleven phases. And then he still has one more form left, where he goes all-out with the Bullet Hell in a last-ditch effort to kill you.
Afterbirth's Ultra Greed due to having a unique gimmick involving coins that, if not destroyed, can unlock doors that summon enemies, and Hush due to being the game's biggest example of Bullet Hell but this time in a 2x2 room. Both also have damage resistance which scales depending on the damage you're doing, so even if you're on the most powerful run of your life, they still won't become an Anti-Climax Boss and die in one hit.
In Afterbirth+, we have Delirium, the ultimate boss of the game. While he starts in his true form, he starts mimicking the other bosses in the game, including other Final Bosses, with absolutely insane attack variants.
Breather Level: Even during the Brutal Bonus Level, there will occasionally be rooms with only a fly or a pair of helpless grubs, which still recharge your special item and have a chance to drop items. There will also always be some empty rooms, and it's possible to spend quite a long time in the arcade with virtually no chance of death.
Literally all of the humor qualifies. The best example is probably the infamous "Yay, cancer!" — a description of a trinket that's literally a tumor and increases the rate of fire.
The Aprils Fool challenge has you go through the game with several interface screwups such as a broken map and items that are disguised as other items. Coins are golden hearts, red hearts are actually coins, and so on. To top it all off, you'll soon come across The Bloat. And The Bloat, and The Bloatagain. That every boss is replaced by this loathed opponent does at least give the annoyances of this challenge a touch of hilarity. The fact that you're basically immortal in this mode thanks to coins being soul/black/gold hearts only adds to it. Unless, of course, the game decides to kill you by giving you a card that turns out to be Suicide King or making you roll Plan C with your spacebar item, in which case you will likely alternate between laughing and cursing out the Random Number God.
Compared to the Halloween Update's Sheol, which tested your skills with the base game's items and had an awesome boss at the end, Wrath of the Lamb's Cathedral, which further tested your skills and had a brutal boss at the end, and a later update's Chest, which essentially starts out with four Item Rooms and contains mostly bosses, Rebirth gives us the Dark Room, meant to be the demonic counterpart to the Chest. It succeeds in all the wrong ways, with the level starting out with four Red Chests instead of trading four keys for four items and having much more unfair rooms. Its only redeeming counterparts are a great boss fight at the end and the fact that non-Red chests still pay out with items.
Afterbirth added an optional level named "???" that unlocks one of the last endings once it is cleared for the first time. However, it is just a single room with a few items and then the Bonus Boss. And yet it gets a song that lasts for over 2 minutes. Not quite what people expected at release.
Afterbirth+ added what's meant to be the ultimate final stage and boss of the game. It's just a mash-up of previous levels and bosses. The Void and its boss, Delirium, are fitting narrative-wise, but it all still feels very underwhelming to a lot of people.
Ear Worm: Try finding a player that doesn't have Sacrificial stuck in their head. There's also the 8-bit version that plays in Arcades, which might be even catchier.
Ensemble Darkhorse: The Dark Bum from Rebirth quickly became one of the most wanted items. When it was severely nerfed, there was fan outcry for him.
Sissy Longlegs, while not a very powerful item, is cute in her own way. Her description "she loves you" tends to give her a free pass on rerolls.
Bumbo from Afterbirth has won a lot of fans over with his array of rather useful abilities. The fact that he grows by collecting money, which tends to be rather useless later on, also helps. Edmund seems to have been very aware of his popularity, as he is now receiving his own Spin-Off game.
Dry Baby is also considered a god-like item due to its ability to block pretty much all shots and damaging every enemy in the room each few shots it blocks.
The character released in the final booster pack, The Forgotten, has been very well received by the fanbase for his unusual playstyle and the amount of work that went into his appearance and animations. It helps that unlike The Lost and The Keeper, who both had similar complicated means of unlocking but ended up being Tier Induced Scrappies, The Forgotten is a viable character in his own right.
Fandom Berserk Button: Using the Flash Filter in Rebirth will often get people to mock you for it, particularly those who use 4chan. This is most likely because of how blurry the filter looks compared to the non-filtered game, and the fact that the filter was only added in as a joke against the people who hated the pixel-art style of the game.
When under the effects of Whore of Babylon, your character leaves a small puddle of blood rather than the usual puddle of pee left at low health every time you enter a room. This may be a reference to past conceptions of what periods were (a curse due to Eve's actions of original sin) or even to the Biblical passage introducing the Whore of Babylon, "...and I saw a woman sit upon a scarlet coloured beast..."
Knights and their many variants are hard to hit, since they're invulnerable in the front and have unpredictable movement patterns. Some even turn to charge you. Past a certain point, piercing is practically required to survive. It certainly doesn't help that there's a boss version.
Hosts take cover and shoot 3-way shots. Sometimes weird maneuvers must be taken for them to show up. There is a red host variation which cannot take cover, but it shoots a 5-way spreadshot and fires more often.
The many varieties of flies fit the trope better. Especially the ones that shoot at you, or explode in a flurry of bullets upon death.
Similar to the flies, the many variants of spiders fit this as well. Not that hard to kill (once you learn the basics of dodging), but they are on every floor, many bosses and some mooks spawn them, and they are just random enough in movement to chip damage you to death over the course of a long run. Good luck trying to kill them with the Ipecac or Fetus in a Jar.
Lil Haunt, the mook version of The Haunt, is an extremely cheap enemy. Their movement pattern is designed to lead you, which makes it very easy for them to corner you (but also extremely easy to control them if you know this). They have a bullet attack which has no tell or consistency. They are tougher than most mooks their size. Finally, they make the boss fight against The Haunt that much more annoying.
Wizoobs, the ghost enemies that spend most of their time phased out of existence except to spray a hail of bullets in your face. Their attack isn't too hard to dodge, but they have a boatload of health, don't stay tangible long enough for you to deal any meaningful damage, and tend to spawn in packs of six or more. No matter what items you have, they will take a disproportionately long time to kill. Afterbirth adds in Wizoobs which shoot Brimstone to the mix, only making their infamy worse.
Bonies. Not terribly dangerous or tough, but their bone throw has absolutely no tell, and they will use it almost without fail if you try to line up with them to take a shot, making it very likely that one of them will hit. They're also some of the few enemies that Azazel has trouble dealing with, as his short range is pretty much an invitation for a point-blank bone to the face.
By the time you reach Chapter 6: Headless Horseman Heads. Their size, speed, and health make them take a while to kill (unless you're ridiculously overpowered), they fire three-way blood shots, and they often spawn in groups of two or three, or are accompanied by either Demonic or Holy Leeches. By this point in the game they aren't really that dangerous, but they're certainly annoying to fight through.
Fat Bats are both a literal and a metaphorical example of this. They come with a boatload of health, have unpredictable bullet attacks with no tell, and try to avoid your shots. On the other hand, they're also slow and don't shoot very often (and when they do, it's relatively simple to dodge). As a result, they're not exactly dangerous so much as tedious to fight.
Imps. Any time they're not casually avoiding your shots they're firing a very fast barrage of shots directly at you. It's not uncommon to spend half a minute just trying to kill one, especially if it's a champion version.
Stonies cannot hurt Isaac, but what they can do is block Isaac's shots at other enemies, which gets annoying very quickly. Especially since Stonies are Invincible Minor Minions and will only die when every other enemy in the room has died. It didn't take long for Edmund to Nerf them by causing them to have to stop and catch their breath every five seconds, which downgraded them from Demonic Spiders.
Mushrooms in Afterbirth+. They have above-average health along with boosted defense when they take cover, and tricky Clotty/Clot shot spreads. That alone wouldn't qualify them for this, but as Host variants, they can spawn from breaking skulls. Oversight or not, this means that destroying skulls with a break-on-touch ability is no longer a guaranteed safe option (Hosts do not deal contact damage, but Mushrooms do), which limits an easy way to acquire tarot cards, runes, black hearts, and Dry Baby/Ghost Baby. Thankfully, this has been fixed as of the fifth Booster Pack, though console users will still have to deal with the issue as Booster Packs 4 and 5 have yet to come to consoles...
Harsher in Hindsight: All of the Guppy-related items were inspired by a real cat who McMillen owned — "owned" because the real Guppy passed away in August of 2014. Where this trope comes in is that quite a few of these items clearly show that the cat in question is dead... Rebirth's teaser trailer, which features a photorealistic decapitated cat head modeled after Guppy, did nothing to help matters because it came out exactly a year before he died.
Hype Backlash: Considering that The Wrath of the Lamb expansion available for the original version of Issac was absolutely enormous and dirt cheap, many fans thought that Afterbirth, the first expansion for the remake, would be comparable to WOTL. It is nowhere near that size, which many fans have felt ripped off by. While many praise new additions like the genuinely interesting (if somewhat buggy) character Lilith, the fantastic and fun Greed Mode, and many of the new items being very fun to toy around with (and boasting even more tasty synergies to fool around with), there are a staggering amount of issuesnote The absolutely massive amount of bugs, needless difficulty increase from Rebirth, constant patching (to not fix the bugs but instead make the game tougher), the disappointing challenges and transformations, the 109 incident and Edmund's incredibly poor handling of the situation that have left a good portion of the fanbase extremely upset and disappointed.
When the game was barred from release on the Nintendo eShop due to the religious content, all hell broke loose.
Thankfully no longer the case as of 2015. Nintendo's former head of indie relations, Dan Adelman, managed to reform Nintendo's outdated and restrictive eShop policies prior to leaving the company to go independent, which finally allowed Binding of Isaac: Rebirth to see an official eShop release on the New 3DS and Wii U in an uncut state, and eventually a release on the Switch in 2017.
The AfterbirthAlternate Reality Game, or rather what was initially believed to be one. After Edmund and Tyrone (the programmer) teased the community with what seemed like another ARG, it turned out there was none. The missing content from the game was just added after 109 hours, with a patch that on top of that severely (if briefly) nerfed Azazel and a few powerful items. Cue community's complaints, which mostly died down after the real ARG.
It Was His Sled: Let's just say that anything in the game that can be considered a spoiler tends to fall into this territory very quickly. The existence of ??? and The Lost, for instance, tend to barely even be treated as spoilers by the community.
Memetic Badass: Certain items have this reputation. However, said items are generally useless or arguably downright harmful.
Before Rebirth, Abel (a mirrored familiar with the power of basic familiars) was the most common example, but since then, it had to share the spotlight with Aquarius (tracks low-damaging trail of tears on the ground).
On the bosses' side, there's The Bloat. While this game certainly doesn't skimp on the brutally difficult bosses, none of them (not even most of the Final Bosses) have obtained the same reputation for destroying runs as The Bloat has.
One of the most popular emoticons on Twitch is BibleThump, which is Isaac crying.
"It's not a won run yet!" tends to be used for very powerful runs, which came about due to Northernlion consistently saying it for runs which were very easy.
People messing around with the intro narration has resulted in The Isaac of Isaac. One of the Community Remix devs is currently making a mod that replaces all item textures with Isaac, turning this masterpiece into a playable experience.
CHUB DISLIKES SMOKE!explanation The Rules Card item is infamously useless. It's supposed to give the player hints, but not only is the hint in question (which seems to be the only thing the card ever pays out with, despite there being confirmed to be a ton of other, more useful hints for other things such as Boss Rush) referring to something rather obvious, very few people play the game without visiting the wiki anyway.
Yay, Cancer!explanation Cancer is widely regarded as one of the best trinkets in the game, as it effectively doubles your tear rate and therefore damage output. The Black Comedy of getting cancer being one of the best things that can happen to you in this game has not been lost on the fanbase.
Ultra Greed's Assexplanation The Final Boss of Greed Mode, Ultra Greed, has, for whatever reason, a very well-detailed butt. This has not gone unnoticed among the community.
109. explanation Before the November 4th patch, the Greed Machine used to max out at 109. Many believed that this was a code and part of the ARG. Due to the amount of speculation regarding the number before the patch, and the controversial reveal that it was a countdown, it has since become (in)famous among the community.
Are you enjoying the steak? Remember to chew it slowly or else...explanation Edmund got very angry when dataminers leaked the secrets of Rebirth. Both he and Tyrone went into an interview and said that the community "swallowed a hundred dollar steak in one bite", which lead many people to ironically refer to the game as "the steak". People (especially Imageboards) started joking about how Edmund is nerfing the items just to ruin the fun, or in other words, "not letting you eat the steak too fast".
Shh, don't let Edmund hear about x, he might nerf it...explanation Afterbirth's release was infamously followed by a series of patches focused on needing items. As a result, fans often jokingly hesitate to refer to any item as "overpowered" for fear that Edmund might hear about it and Nerf that item in the next patch.
Two words: "Dank Depths".explanation The new alt floor of the Depths, introduced in Afterbirth, which quickly became a joke.
FUCK BLOATexplanation As shown in That One Boss below, the game has plenty of tough bosses, but the Bloat is probably the best known and most detested, to the point where Reddit has an entire subreddit (r/FUCKBLOAT) devoted to complaining about him.
SHAKA SHAKA DING DINGexplanation The "lyrics" of Shadowdance, Antibirth's theme for Sheol. It quickly became memetic on Reddit, to represent the hype for the mod and Antibirth as a whole.
Moral Event Horizon: Isaac's mom crosses it at the start of the game when she tries to murder her own son.
Most Annoying Sound: Isaac's 'hurt' sound when he takes damage has no variation (at least pre-Rebirth), and if you have to hear it several times in a row, it quickly becomes grating.
The jingle that plays when finding a Secret Room in either version. The Rebirth one is notable enough that it plays when selecting Rebirth on the New 3DS menu.
The narrator calling out the name of any pill or card used, especially if it's one with a beneficial effect. The really nice voice doesn't hurt.
The angelic choir when you pick up a Soul Heart, or the triumphant note of picking up an Eternal Heart.
The combination of "pinball bonus"-like sounds when you use a pill with a positive effect.
The sound of an Angel or Devil Room opening up after a boss kill. Unless you have to fight Krampus, that is.
Narm: The True Final Boss of Rebirth is undeniably awesome in every way...except for his name. His name is Mega Satan, which, while intended to make him more awesome, leads to this instead.
Nausea Fuel: The environments and enemies are all really gross, from the giant turds lining the floors, the enemies that look like giant anuses firing out laser beams, grotesque monsters lined with all manner of horrific markings... ich. The Rebirth remake adds more details, including things like tiny maggots crawling around the floor in large numbers.
The Womb's music track in Rebirth, "Viscera", contains... indescribable fleshy sounds that might be a little unnerving to some players.
The Scarred Womb in Afterbirth may be the most nauseating environment to look at in the entire game. The name should sum it up quite well.
There is a "Gulp!" pill, which destroys trinkets and adds their effects to you permanently - Presumably by swallowing them. There are trinkets like a used diaper, a fish's head, the heart of a child... Draw your own conclusions.
Samson in Rebirth, following his transition from the original game. While he was originally despised for having low health and having an ability which lasts only one room, the remake greatly increased his health and made his ability not only easier to achieve, but also last the entire floor.
The Lost in Afterbirth. Originally a One-Hit-Point Wonder whose only special ability was flying, the expansion greatly buffed him three times. He now starts with the D4, spectral tears, and the Holy Mantle (though the latter item must be unlocked first), which makes the game significantly less frustrating for those playing as him. Another patch made his unlock process significantly easier to accomplish, which no longer makes it a Guide Dang It! affair.
My Reflection is a particularly infamous one, as it just makes your tears boomerang around wildly, cutting your range and making it hard to aim. Some combinations using it will screw you even harder, such as combining it with IPECAC or Bob's Rotten Head, causing your explosive projectiles to boomerang right back at you. Even worse is that the Suicide King challenge in Rebirth sticks you with the My Reflection + IPECAC combo for the entire run. It works surprisingly well with Azazel, however, as it's one of the few items that increases his otherwise short range.
Bob's Brain and BBF in Rebirth. There's nothing worse than being in the middle of combat and having them respawn and explode on top of an adjacent enemy, catching you in the blast. Sometimes, BBF can even damage you as soon as you enter a room! Bob's Brain, at least, was toned down a bit in Afterbirth, as it now can't be fired for a few seconds after it spawns or after you enter a room, preventing surprise explosions.
The Cursed Eye. While the quadruple charge shot is nice, if you are hit while charging the shot, you will be teleported to a random room. This makes fighting bosses very problematic, as even one mistake can warp you away and ruin all of your progress. Fortunately, this drawback is easy to work around, and can even be beneficial in some circumstances. Most notably, allowing you to take a free item from the Boss Rush room.
The Stopwatch, which is frowned upon for either being too powerful or too weak of an item, depending on what version of the game you're playing. In Rebirth, it is a huge Game-Breaker which slows down enemies and projectiles for the entire game. In Afterbirth, however, the slowdown effect not only lasts one room, but only activates if you take damage.
Rebirth also gives us Soy Milk, which, at the cost of slashing 80% of your damage and tear size, massively boosts the firing rate of your tears, to the point that a starting Isaac with Soy Milk has enough of a fire rate to shoot 30 tears per second. Unfortunately, the game has a hardcoded limit of 15 tears per second, meaning that while it's technically a bit more DPS than your default tears, that's only if you make every shot count. Given the game's enemies and their erratic movement patterns, making all your tiny tears hit their mark so the damage output is at least decent is a pain in the ass. The DPS is so poor, all bosses become Marathon Bosses, and even flies take a lot more shots before they're down. And to add insult to injury, it's a special item, so once you see it, your chances of a really good item in your current run fall dramatically! Only once you gain a lot of DMG ups or synergize Soy Milk with other certain items does it become a Game-Breaker, due to its high firing rate carrying over. Fortunately, in Afterbirth, Soy Milk is no longer a special item, meaning that it no longer interferes with your ability to get really good items just by showing up.
Of all items, Dr. Fetus is this in Rebirth. In the original, it was seen as a borderline Game-Breaker due to its tremendous damage output, but also carried a high chance of damaging yourself. In Rebirth, Dr. Fetus bombs had the self-damage reduced, but also suffered a massive damage drop, meaning that it now fails to consistently One-Hit Kill many normal enemies and kills bosses very slowly. It did also receive an increased fire rate, which theoretically makes Dr. Fetus an overall damage upgrade, but in practice tended to cause bombs to knock each other around — often into the player's face. It doesn't help that fellow explosive attack Ipecac has the same self-damage, but deals much more damage to enemies. Fortunately, Afterbirth restored Dr. Fetus to its former glory.
Afterbirth also brings us the Glass Cannon. On release, it reduced the user to half a red heart, but gave you an on-command massive tear with scaling (but always high) damage. However, as of the November 4th 2015 update, it now reduces you to half a heart — including soul hearts and black hearts — turning the user into, appropriately enough, a Glass Cannon. To say that people are not amused is a massive understatement.
The Butter Bean introduced in Rebirth. It's a spacebar item that only has the effect of producing a small fart that can knock back some enemies. At least it recharges spontaneously, and in Afterbirth it can deflect bullets. Afterbirth+ removes it from this category, as swapping it with another item repeatedly can transform it into "Wait What?", an identical-looking bean that loses the fast recharge time in exchange for creating a circle of rock waves around Isaac.
The Wiz, which doubles rate of fire at the cost of sticking you with the "R U A Wizard" effect for the rest of the run, forcing you to shoot diagonally. Given that the game is based around being able to shoot in the cardinal directions, meaning that "R U A Wizard" is generally considered a negative effect, it's not a very popular item.
Tiny Planet is in roughly the same boat as Soy Milk. Sure, it's a stat upgrade and has some interesting synergies, but the orbiting tears on their own have short range and are nigh-impossible to aim, meaning that players tend to avoid it like the plague. It doesn't help that the effect combines badly with certain strong items, such as Mom's Knife and Dr. Fetus.
Curse of the Tower is a passive item that spawns Troll Bombs randomly around the room each time you take damage. Which usually results in the player being blown up and taking even more damage, especially in half-size rooms or if they're unlucky enough to also have an item like Bomber Boy or Scatter Bombs. It also makes Devil Beggars and Blood Donation Machines virtually unusable, as they tend to get blown up immediately after one use.
Self-Fanservice: Some fans have a habit of portraying the playable characters as adults without the Super-Deformed art style, often just keeping two traits about them: Their starting accessories/hair styles, and the fact that they're naked.
This happens most often to Eve. It might have something to do with her starting item...
Lilith also tends to get this treatment in fanart. Given her long red hair and gameplayschtick, it's probably not surprising.
More bizarrely, there's a moderately popular depiction of Delirium as a Slime Girl.
The No-Damage Run achievements. At least they're mercifully divided into groups, so you don't have to go through all eight in one run.
The king is the Dark Boy (Depths) No-Damage Run. That level set has just the right combination of pits, Demonic Spiders, Goddamned Bats, indestructible moving spike blocks, and cheap-as-hell bosses (plus Mom) to make it an absolute nightmare to get through, no matter how absurdly overpowered your character is. Even the Womb is easier because it does not have pits. Rebirth made the Womb somewhat more difficult by adding pits.
Rebirth ups the ante on that one with Dead Boy, achieved by completing one of the game's Brutal Bonus Levels, The Chest or the Dark Room, without taking damage. Here's hoping you packed a Holy Mantle... though it is slightly easier on The Chest, as four free (as long as you have keys) items are available from the starting room, and there's a chance to find more after completing every vicious room.
Rebirth has The Lost. Unlocking it is a massive Guide Dang It! and a Luck-Based Mission for the first part, though you can mercifully use seeds. Then, once actually unlocked, you have to do no damage runs of the entire game through both Brutal Bonus Levels (Mega Satan is optional) and the boss rush, and then do it all again on Hard mode to unlock the Godhead.
Assembling Super Meat Boy and Bandage Girl in Rebirth. In vanilla Isaac and WOTL, assembling Super Meat Boy wasn't too difficult to do as long as you got the Book of Revelations early enough. And you didn't have to assemble it to get the achievement, just kill all 4 of the Harbingers in one run. Unfortunately, the Book of Revelations no longer guarantees a Harbinger boss fight, instead giving a higher chance to run into them. The real kicker is that they now drop a Cube of Meat or a Ball of Bandages, so you have to hope the first one drops the item you want. Running into the Headless Horseman or Conquest will also ruin your chances of getting the achievements. Counter-intuitively, these achievements are actually easier if you go out of your way to avoid unlocking Conquest (which requires getting ten Angel Room items). Once Conquest is unlocked, it becomes downright impossible to manage a fair playthrough where you get the whole set. It's considered a lot less luck-based just to set up a way to infinitely recharge the Monster Manual to get a level 4 Meat Boy/Bandage Girl. It says something that these achievements have a lower completion rate than almost every other achievement in the game, second only to the shop unlocks and all of the Lost's achievements. Mercifully, Afterbirth made this incredibly easy to earn with the addition of Greed mode and Lilith. Lilith's active item, Box of Friends, duplicates any familiars she has for the room it's used in. With Cube of Meat/Ball of Bandages, the effect is an immediate upgrade with each use. Greed mode's wave mechanic allows you to use the box at least three times in a row, since the charges accumulate with each wave. In tandem, this means you only need to find one of either item to get the associated achievements. Boss Rush or a 48 Hour Energy pill in the main game will also work. Afterbirth + went a step further and added the Potato Peeler, an-infinite use spacebar item which removes one red heart and generates one Cube of Meat along with a damage increase. Four hearts and you've got it.
Collecting all of the items for Platinum God and Real Platinum God in Rebirth is far more annoying than in the original. This is mostly due to two reasons: the Secret Rooms and Steven. Secret Rooms have a much greater variety now, most of which do not contain items, which combined with a larger number of exclusive items means it is that much more difficult to get everything from that pool. Most resort to Loophole Abuse with the D6, Judgement cards, and mushroom drops. Steven was originally a nightmare to find in Rebirth due to only being a rare boss drop, but Afterbirth has since fixed this by putting Steven back into the golden chest pool.
Two achievements in Afterbirth+ depend on Daily Runs. 'Dedication' is for participating in, but not necessarily winning, 31 Daily Runs in a row, which is generally regarded as a month-long chore and impossible for those who don't have access to a computer every day for a month. 'The Marathon' is for winning 5 Daily Runs in a row, albeit they don't have to take place on consecutive days. Given that some Daily Runs task you with beating Mom with an easy character, and others require you to make it to Mega Satan with The Lost, it's not uncommon to find threads on the Steam forum warning users to stay away from a particularly bad daily. A multitude of threads popped up on January 29th when the Daily Run included no damage-up items at all, yet still required players to beat Mega Satan with Lilith. To make things worse, while they only unlock a trinket and a pill, both of these are necessary to unlock the 1000000% completion achievement, meaning that you could have beaten every challenge and every boss with every character, but if you can't take part in 31 Daily Runs in a row, you'll never unlock the final achievement in the game. Thankfully, a later patch made it so that the 31 Daily Runs didn't need to be consecutive, removing Dedication from this territory.
The achievement ZIP! requires beating the Lamb in under twenty minutes. Just getting to Mom on a good run takes nearly twenty minutes. Rushing through the Womb, Sheol, and the Dark Room on top of that basically requires having found the Treasure Map and Compass so you waste as little time as possible. While there's the possibility of using a Sacrifice Room in order to teleport straight to the Dark Room, this is very much a Luck-Based Mission. You not only have to have one spawn on any floor up to the Depths, you have to be able to take at least 12 hits on that floor (if you're lucky, the Sacrifice Room will spit up 7 Soul Hearts to make that easier, and you can go back for health pickups) and beat both mandatory Angel fights in the process. Once you make it to the Dark Room, you better hope you have good enough items to track down and kill the Lamb in a reasonable time frame. In short, 'a lot has to go right for this achievement to be remotely possible.
Unlocking the Forgotten makes the Lost look like a cakewalk by comparison. First, you have to beat the first boss within a minute, which can be hit or miss. Once you've done that, a shadow of a shovel handle appears in the starting room. Bomb it to get the Broken Shovel. To get the other half, you have to beat the Boss Rush. Sounds easy, right? Wrong. The Broken Shovel is essentially the Toenail trinket on steroids. Two Mom's Foot enemies will attack you constantly, and activating the Broken Shovel only serves to remove them from the current room. It has a four-room charge. This means you have to rush through a fair portion of the game under constant attack. You can't cheese it by picking up another active item on the floor, either; ditch the shovel and it disappears if you leave the room. On the plus side, the feet will kill your enemies and break bombable things for you, if you can trick them into it, and having Pyromaniac/Host Hat renders them harmless.
Mom's hand during the Mom boss battle, not to be confused with the Mom's hand monster in Rebirth. It comes out to swat you if you hang around the doors too much, and is near-instantaneous. It's avoidable, but you probably won't manage to do it on purpose. Playing as The Lost? Game over.
The Bloat's brimstone attack, which once again has no tell and hits almost instantaneously. And he'll use it without fail if you get in range while he's not using another attack.
The Adversary's Brimstone attack. It's telegraphed by a unique roar, but that's of little comfort when the beam actively curves to hit you. While it is possible to dodge by getting close and circling the boss, this attack becomes a terror when two Adversaries are in a single room and the one in the other corner unleashes the beam.
Mega Fatty, an otherwise easy to dodge if spongy boss, has one really annoying attack. He can, with almost no warning, leap from his current position to where you're standing in less than a second, which is practically undodgeable if you're standing still.
Brimstone beams are That One Attack for the game as a whole. They have no travel time, cross the entire room, pass through all forms of cover, and linger for a couple of seconds. Fighting multiple enemies with Brimstone attacks in a room generally means you run out of room to dodge very quickly.
Of course, when you have them they have the same advantages as the boss ones and items like the Head of Krampus, Tammy's Head (if you have brimstone), and especially Mega Blast can deal a lot of damage with their beams. Tammy's Head is stronger with Brimstone than the Head of Krampus because it shoots in all directions instead of the cardinal directions and recharges after a single room. This is all if you can get the items in the first place (Azazel at least benefits more from Tammy's head, see below in "Tier Induced Scrappy").
Hush's Continuum attack, where his bullets wrap around the screen. Several factors make this attack more difficult to avoid than it sounds on paper. First, the bullets move faster the longer they stay in the air, and by the time they finish their wrap around will be moving extremely fast. Second, he sprays the bullets in an expanding cone, so they become a large wall when they return from the other side. Third, the bullets wobble as they travel, making predicting their patterns and finding a safe spot difficult. Fourth, he can suddenly switch directions and unleash a new bullet spray before the old one is done, overlapping them and making dodging nearly impossible. Finally, even if you do manage to figure out where the safe spots are, the boss can fire from any number of positions, forcing you to figure out the new safe spot on the fly.
The Cellar can be a much harder starting point than The Basement, usually involving harder enemies and rooms with a borderline fetish for spider enemies. In addition these levels can frequently stick you facing either The Widow or The Haunt as your first boss battle of the run.
Necropolis. Not only is it home to quite a few Demonic Spiders (such as Hangars and Masks + Hearts) and numerous spike traps, but it also holds some very annoying bosses like The Bloat and The Mask of Infamy. Fortunately, the latter only applies for Necropolis 1, as Necropolis 2 always has Mom as the floor's boss. There's still the risk of them spawning in Boss Challenge rooms, though.
The Dark Room, when compared to fellow Brutal Bonus Level The Chest. While the four initial chests in the latter all contain items, the ones in the former are red chests with the usual fare, meaning that there is no guarantee of getting anything that helps you survive the level. Additionally, the Dark Room tends to contain more dangerous enemies than The Chest, including the likes of multiple Fallens or even Mask of Infamy.
The Womb on Greedier Mode. Four waves spawn with less than a second of delay. If you aren't overpowered by now or have health to spare, you're dead, no question.
The Flooded Caves, where Chargers have a higher chance to be replaced with their slightly tankier, diagonal shot-shooting cousins known as Drowned Chargers. Many of the "drowned" enemies spawn them as well, including the level's Mulligan variety, which can quickly fill the room with enemies that can overwhelm the player character in a run with low DPS by that point. The infamous "single line of ground over a bit with five Boom Flies" room can still appear, and the flies have a chance to be replaced with Drowned Boom Flies, who have a cardinal retaliation shot and spawn, yet again, Drowned Chargers. Not miraculously getting flight by Chapter 2 could easily mean a death sentence. To top rub salt in the wound, one Super Secret Room variety that is almost completely uselessnote It consists of nothing but a narrow cross-shaped path leading to a black poop surrounded by spikes. Black poop can be used to damage enemies, but there are no enemies in the game. At best, the black poop could be rerolled with D12 and the spikes could be used to activate some items that work on damage, but those are both highly situational. is the one with the Flooded Caves skin. Booster Pack 4 of Afterbirth+ made it even worse with the addition of a unique type of worm enemy that fires high-arcing shots that "predict" where the player character tries to run to.
That One Sidequest: Most of the challenges, especially the ones included in Afterbirth, qualify as this. Notable offenders include:
The Suicide King challenge in Rebirth. Have fun playing the entire game with exploding tears that boomerang right back in your face!
The Family Man challenge is probably the the hardest of the base game. You're blindfolded, and your only means of damage are through three familiars. Thankfully, one of them is Rotten Baby, which scales with your damage, but other than that, you're gonna have a very hard time trying to damage enemies even a little bit. It's borderline impossible to complete the challenge without resorting to resetting until you can get a Cube of Meat or Ball of Bandages on the first floor.
The Speed! challenge in Afterbirth. Enemy movement and bullet speed are dialed up significantly while you start as basic Isaac. There's Treasure Rooms, but that's little comfort when bosses like Gurdy Jr. can move twice as fast and become practically unavoidable. Oh, and if you don't finish all the way to It Lives in under 16 minutes, you get half a heart of damage every few secondswhich can kill you!It goes to the point it's almost impossible to even beat the first floor if you get a hard boss unless you get a good start. It's basically saying "reload until you get Brimstone or something else that kill instantly, otherwise you lose." A patch eventually increased Isaac's movement speed as well, making the challenge slightly more manageable in that you'll at least be able to outrun most enemies that chase you.
The Brains! challenge, again in Afterbirth. You're not only blindfolded, but your only offensive weapons are three Bob's Brains, which is a Scrappy Weapon infamous for its tendency to blow up right in your face. What makes this worse is that you're playing as ???/Blue Baby, making it more difficult to recover health, and you have to fight all the way to the Chest.
The Guardian challenge, once again in Afterbirth. You must protect Isaac's Heart which isn't following you, but rather the Punching Bag that wanders around the room. Oh, and the Punching Bag is the one that takes damage, not the heart. You have no real control over whether or not you take damage, as all enemies attack the Punching Bag rather than you. Hazards like red poop and spikes turn the challenge into a Luck-Based Mission due to the fact that, if the Punching Bag touches a hazard just once, you lose a lot of hearts instantly!
Most challenges where you're blindfolded and thus unable to fire tears falls into this category, such as "Cat Got Your Tongue" (rely only on flies and Guppy's Hairball for damage) and Solar System (orbitals only).
The Ultra Hard challenge in Afterbirth+ lives up to its name. You are Isaac (minus the D6) stuck with Curse of the Lost, Curse of the Maze, Curse of the Blind, and Curse of the Labyrinth with the possibility of additional curses on top of those. The four permanent curses furthermore cannot be dispelled with the Black Candle or Dagaz Rune. All enemies and bosses that have Champion variants will be Champions, no exceptions. What's worse is that the challenge will never drop hearts - ever. The only way to get health is to get HP Ups, items that directly give you health (items that drop hearts on the ground do not work), or get a regenerating item ala Placenta or Blood Leech. What's worse is that the end goal is beating Mega Satan, which sets up a long and frustrating road, and the Ehwaz Rune doesn't work, so you can't skip any floors either. Oh, and your reward for all that effort? Samson starts with the Child's Heart trinket. A trinket you'll almost certainly discard because it will replace other, more useful drops like keys.
Unlocking the final character of the Afterbirth+ expansion (the Forgotten) is this, besides being also a Guide Dang It!. For starters, you must beat the first boss in under a minute, which is practically a Luck-Based Mission. Then, you must go back to the first room and bomb the center; this will make the Broken Shovel appear, which has the nasty effect of making Mom's feet appear nonstop every couple of seconds and try to attack you (although you can "use" the Shovel to neutralize the effect every fourth room). You must then race the next six levels with this handicap and defeat Mom within 20 minutes, enter the Boss Rush, and defeat that. After that, the Broken Shovel becomes the non-cursed Mom's Shovel, and it's "just" a matter of reaching the Dark Room floor and dig up a mound of dirt.
Samson in the original game. To put this into account, he's more despised than the game's resident (Lethal) Joke Character. He starts with a meager one heart container and crappy damage output, and while his starting item increases his damage for killing enemies, it's useless against roughly half the bosses in the game since the boost resets every time you enter a new room. In other words, anything Samson does, Judas can do better.
Eve, too, to a lesser extent. She starts the game with below average health and damage, and her initial abilities are all essentially Cast from Hit Points. Do the math. It's so bad that, before the DLC, the Lethal Joke Character actually had a higher completion rate, despite being more joke than lethal.
Rebirth gives both of these characters buffs. Samson now starts with three hearts and his damage stacks don't reset until he leaves the floor. Eve's Whore of Babylon will trigger at a full heart instead of half a heart (it still triggers at half a heart for everyone else). Cain, however, was hit hard with the nerfbat, as his Lucky Foot no longer recycles bad pills. Afterbirth eventually buffed Cain by starting him out with the Paperclip, provided it is unlocked.
Azazel is often frowned upon for being largely unbalanced compared to the other characters. To explain, he starts with three black hearts (but can acquire regular health through powerups), flight, and a short-range Brimstone attack. The range issue is at best minor, and Azazel can clear rooms like nobody's business. With a little skill, Azazel can easily make it all the way to Mom in time for the Boss Rush without any significant powerups. With powerups, he's a murder machine. He eventually got nerfed in Afterbirth by having his fire rate lowered, but this can easily be undone with a couple Tears Up items.
How about The Lost? He can fly, but he's a One-Hit-Point Wonder and doesn't even start with any items besides one measly coin. The fact that one of his item unlocks requires you to beat every final boss (save for Mega Satan) on hard certainly does not help matters. Fortunately, as Author's Saving Throw mentions above, he eventually got the buff he deserved.
Lazarus has negative luck and short range but starts with a pill and the ability to resurrect with 1 heart; problem is, the pill can randomly screw you and the resurrection isn't something you should rely on the first place. So, when compared to the other characters, Lazarus is generally considered to be the most boring.
By getting 1000 coins in the Greed mode donation machine, you unlock The Keeper (which is basically a playable shopkeeper). Instead of hearts, he has two coin slots; any kind of damage takes one coin, but taking another coin on the floor heals it back; all hearts are converted into blue flies. Only one item in Afterbirth + has the ability to increase his health (up to 6), and you can decrease it with items or Devil Deals that take away a heart. This means virtually all health increasing items are worthless unless you've lost one coin slot already. Two heart deals are instant death without some sort of revive. Furthermore, coin damage counts as red heart damage as far as Devil/Angel Rooms are concerned, so without the Goat Head you can never take damage if you want access to them. He gets a triple shot to start, but the tear speed is abysmal and you'll be begging for tear increasing items. On the plus side, if you find a Swallowed Penny or the less reliable Piggy Bank (it is programmed to drop less coins than normal on Keeper), you're essentially immortal as long as you have two coin slots. Even his starting items are at best mundane. He begins with a single bomb, and through unlocks can have the Wooden Nickel, a single coin, and the Store Key trinket to unlock shops. The items he unlocks are at best situational, with the Rib of Greed being the only moderately useful one. In short, Keeper has a mountain of setbacks, but no advantage that makes up for the shocking difficulty.
Viewer Gender Confusion: Mask of Infamy, Lust, and the entire Gurdy family are confirmed female by Word of God. The only in-game indicator for any of these is that the largest Gurdy variant is named "Mama Gurdy," which does not necessarily mean that the others have to be female. And that Lust is pink. Mask of Infamy, which appears as a giant literal mask with a heart, has nothing indicating that she is female.
We're Still Relevant, Dammit!: One of the items in Afterbirth + is Poke Go. By the time the expansion was released, while it still has a regular player base, is largely regarded as a fad of 2016 by most people.
If you thought Isaac was a Woobie before, the Downer Ending multiplies it by tenfold. As it turns out, he is indeed slowly asphyxiating to death within a chest. We are finally given the reason why: He did it to himself. After losing his sister and pets and watching his father walk out on his mother, he demonizes himself and blames everything that happened on him. The entire game is a Dying Dream as he goes insane and slowly suffocates to death.
The lowest level Mulligans don't even try to attack you, instead running away when you approach and cowering in the corner.
WOTL adds a power up that turns you into one. It's every bit as useful as it is horrifying.
The true ending of the game not only ups Isaac's own Woobieness, but also does the same for his mother. Not only does she have to go through losing her daughter, and having her husband leave her, but she finds the little skeleton of Isaac, who had long been Driven to Suicide. Also possibly a Jerkass Woobieassuming that the abuse implications in the items is still true and that Isaac's mother was the abuser.