History YMMV / TheBindingOfIsaac

The song for Downpour, [[https://ridiculon.bandcamp.com/track/river-of-despair-downpour "River of Despair"]], sounds very similar to the Dungeon theme for the original ''[[VideoGame/TheLegendOfZeldaI Legend of Zelda]]''.

* SignatureScene: Found on the title screen, transition screens, and new save files, [[https://i.ytimg.com/vi/KIRU0KvZJh4/maxresdefault.jpg Isaac]] sitting in the basement, surrounded by flies and in the [[DramaticSpotlight light]] of the trapdoor above

** [[WaveMotionGun Brimstone beams]] are this 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 [[spoiler: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).

** 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, which is pretty quiet, plus 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.

** An even more common one is "Blue Baby" for the unwieldy ???. [[spoiler:For the True Final Boss as well as the character.]] This was ascended as of one of the updates, with his will being signed as "??? (a.k.a. The Blue Baby)" This nickname is so popular that his character card in ''The Binding of Isaac: Four Souls'' was introduced as "Blue Baby (aka ???)".

** 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†'' had to add a bunch of features and achievements tied to this floor just to give players an incentive to go there.

** '''The Lost.''' [[JokeCharacter And how!]] He can fly, but he's a OneHitPointWonder and doesn't even start with any items besides one measly coin. He can make unlimited Devil deals as his lack of health means he doesn't have to pay for them, but this is largely mitigated, again, by the fact he dies in one hit. The fact that one of his item unlocks requires you to beat every final boss on ''Hard mode'' certainly does not help matters either. Fortunately, in ''Afterbirth'', he was significantly buffed, as he was given spectral tears and the D4 and Holy Mantle are unlockable starting items for him (though the D4 isn't something you should rely on in the first place). ''Repentance'' added back some of his difficulty as Holy Mantle was nerfed to only give half as many invincibility frames as before, meaning that you'll die instantly to any damage source that does multiple ticks unless you can move away in less than half a second. However, it also replaced his D4 with the Eternal D6 as his starting item, meaning he has access to the same kind of rerolls as Isaac has, but less reliably (which ties in to his status as one of the game's {{joke character}}s).

** With ''VideoGame/ShinMegamiTensei'', especially both games have heavy religious themes.

** With the introduction of Warp Zones to the ''Four Souls'' card game providing characters and items from other series, there were a few curveballs along with the more popular choices. However, most unexpected of all was the inclusion of things from ''Tommy Wiseau's Film/TheRoom.''

* ComeForTheGameStayForTheMods: ''VideoGame/TheBindingOfIsaac'' has thousands upon ''thousands'' of mods in the Steam Workshop, ranging from meme sprite swaps to assistance tools that [[GuideDangIt actually tell you what the item you're picking up does]] to entirely new characters to full-on separate expansions like ''Antibirth'' and ''Abortionbirth''. ''Antibirth'' was so high-quality and beloved by ''Afterbirth+'' players that it was incorporated into the final official expansion, ''Repentance''. Of course, ''Isaac'' is already a very long and difficult game without mods, and SturgeonsLaw definitely applies, so players may have to do some sifting before they find some mods that they both like and are useful.

* SignatureScene: Found on the title screen and new save files, Isaac sitting in the basement surrounded by flies and in the [[DramaticSpotlight light]] of the trapdoor above

* SignatureScene: Found on the title screen and new save files, Isaac sitting in the basement surrounded by flies and in the [[CornerOfWoe light]] of the trapdoor above

** [[spoiler: Isaac believing his mother is trying to kill him? Tragic. [[BonusBoss Mother]] outright ''weaponizing'' this via killing Dead Isaacs and [[GrievousHarmWithABody chucking their body parts at you?]] ''Hilariously'' tragic.]]

** ''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 BonusBoss. And yet it gets [[LongSongShortScene a song that lasts for over 2 minutes]]. Not quite what people expected at release.

* LowTierLetdown: * '''Tainted Jacob'''. Unlike his regular counterpart, Tainted Jacob is played without Esau. However, after 30 seconds or so have passed on a floor, [[CameBackWrong Dark Esau]] spawns and [[FaceHeelTurn starts attacking Jacob]]. This doesn't look so bad, until Esau touches Jacob. When this happens, Jacob turns into his soul, similar to what happens in the Mirror World in Downpour/Dross II. However, there are some core differences: first, Tainted Jacob's soul doesn't have Holy Mantle, so he will die on any hit (unless he already holds Holy Mantle, or has a similar effect); second, while this looks like playing Tainted Lost, Jacob doesn't have the passive "Better Items" and can still find health upgrades... which are useless, unlike in the Mirror World, as any life obtained while playing as Tainted Jacob's Soul will not carry over; third, Dark Esau will still roam around trying to kill Jacob (killing him in one hit, of course). This is basically like playing The Lost from ''Rebirth'' with spectral tears. To add insult to injury, on consoles the transformation from Tainted Jacob to his Soul doesn't have any invulnerability frames and has a tendency to slightly offset the position of the player, with an incredibly high risk of sending the Soul into another enemy, killing him on the spot. Now, maybe you are thinking "Well, let's kill Dark Esau so there are no more problems!", right? Well, on consoles, you can do that! The catch is, it will trigger an explosion that will kill everything in the room, and [[MortonsFork still turn Jacob into his soul]]. So you can basically either play ''Rebirth''[='=]s Lost with an angry guy trying to kill you constantly, or play ''Rebirth''[='=]s Lost. If all that wasn't enough, damaging obstacles like spiked rocks and red poop drain Dark Esau's health ridiculously quickly, and his ArtificialStupidity means he will probably get stuck on one and die unless you actively take measures to prevent it. The only plus side is that, just like any version of The Lost, Devil Deal's items are free to take. Considering the absurd difficulty of some rooms when trying to evade Esau, this isn't really that good. Players actually find it ''easier'' to play Tainted Lost because of the few plus sides that character has. Once again, the difficulty is incredibly high and the game doesn't give you anything to make it easier. A number of players find it less painful to remove Dark Esau using one of several GoodBadBugs[[note]]either by killing him with Eraser, or using Meat Cleaver to split him into two Dark Esaus with less HP that won't turn you into The Lost when they die (though this must be repeated every floor)[[/note]], since without the constant threat of a OneHitKill, Tainted Jacob merely becomes average at worst. [[FromBadToWorse This stopped being an option on PC]], [[https://steamcommunity.com/games/250900/announcements/detail/3087775317090158627 as of the 1.7.5 patch]], as Dark Esau is ''[[TheJuggernaut invulnerable to your tears and bombs]]'' (but not to enemy projectiles), but at least you cannot be touched by him while you have any form of temporary invincibility, he can shred through boss armor, and when you are turned into The Lost, you have a somewhat longer amount of invincibility frames. Oh, and his Birthright effect? It spawns a '''''second Dark Esau'''''.
* After being considered '''''[[HighTierScrappy the]]''''' [[HighTierScrappy best character]] in the game before update 1.7.5 rolled in, '''Tainted Cain''' has become this. Unlike any other character in the game, Tainted Cain cannot pick up items at all — every item that he touches is converted to pickups, and with the Bag of Crafting in hand, you have to [[ItemCrafting craft the items for yourself]] based on seed-based recipes, all of which are comprised of pickups. Since every seed is completely randomized, the items' recipes will constantly change so, with the exception of a few items, there is no static recipe. The one thing that is constant is that, depending on the pickups you keep in the bag is the quality of the item you will receive, which also works against the player's favor; using common pickups can lead to various low-quality items, but sacrificing rare pickups to create the high-quality items can lead to the run becoming harder if the item you receive is egregious and you needed the pickup (e.g. you sacrificed a soul heart you could've potentially used for health to craft [[ScrappyWeapon Bum Friend]]). As a result of the confusion and frustration all of this creates, people don't necessarily have a favorable opinion on Tainted Cain.
* '''Tainted Eden'''. All of Tainted Eden's stats, items, trinkets, and pills/cards get rerolled whenever they take damage. This turns the game into a complete LuckBasedMission, as you're entirely dependent on RNG to give you good items every reroll. Since ''Repentance'' reworked item rerolls, none of the major benefits of rerolling yourself from earlier installments are present — Tainted Eden cannot get permanent transformations, permanent extra lives, and rerolling in to health ups will not heal them. T. Eden's red hearts will also disappear when the items that gave them get rerolled, so you can sometimes go from full health to one heart in just one hit. Or alternatively, you could end up with lots of items that give you empty red heart containers and lose all your soul hearts. The only plus side is that items reroll into other items from the same pool, so if you have a lot of devil or angel items, you're likely to reroll into something powerful. And with red hearts being so temporary, you might think it's a good opportunity to take lots of devil deals. But doing that comes with the big risk of rolling into Dead Cat, which will delete all but one of your heart containers and also not give you any extra lives, as they'll all just disappear when you next get hit. Overall, the only "strategy" to Tainted Eden is to pray to the RandomNumberGod that the next reroll doesn't screw you and avoid any damage at all costs, except for self-damage.
* '''TAINTED LOST'''. Losing the regular Lost's Holy Mantle in exchange for better items seems like a good way to make up for the challenge of playing as a true OneHitPointWonder character, especially since you start out with a Holy Card and have a higher chance of finding more. In practice, however, while there's certainly less of a chance you'll see a quality 0 or 1 item, they can still crop up annoyingly often, and it's possible to go through several floors before you can find another Holy Card to make up for the one you used. It doesn't help that almost every item that would be truly useful for Tainted Lost, like the actual Holy Mantle or any item that grants extra lives outside of Birthright, is hardcoded not to spawn naturally if you're playing as him[[note]]you can still get these items by abusing Spindown Dice, though it's far from guaranteed you'll find both Spindown and the item that rerolls into the one you want in the same run[[/note]]. Tainted Lost's Greedier Mode unlock is considered one of the hardest in the game for one important reason: cards are only available by picking up certain items or in shops (and not even in every shop), meaning there's a very good chance the Holy Card you start with will be the only one you see for the entire run. Two hits maximum against relentless hordes of DemonicSpiders and [[ThatOneBoss awful bosses]] (and if that weren't enough, the way Greedier Mode works makes it entirely possible that you'll get {{telefrag}}ged and waste the shield on a trash mob). '''[[NintendoHard Good luck.]]'''

* UnfortunateCharacterDesign: [[spoiler:Delirium]], being a perpetually melty and pure white BlobMonster is often joked about looking like… a very specific ''[[ADateWithRosiePalms something]]''.

** Angel Rooms are an alternative to Devil rooms first added in ''Wrath of the Lamb'' which in theory provide powerful items without having to pay health. The problem was twofold; first, Angel Rooms cannot spawn until you've skipped a Devil Deal at least once. That means you have to give up the huge power boost Devil Rooms can provide going into the third floor to ''maybe'' get an Angel Room next floor. The other, and more pressing, issue is that Angel Rooms were frequently ''awful''. There were multiple rooms that had no items, and even then many items in the room's item pool are defense-focused rather than offense-focused, with some of them ranging [[ScrappyWeapon from underwhelming to useless]][[labelnote:*]]e.g. Holy Water[[/labelnote]]. There ''are'' standout great items[[labelnote:*]][[GameBreaker Sacred Heart]] especially comes to mind[[/labelnote]], but it simply wasn't worth the risk. ''Rebirth'' and its expansions made this even worse; ''Rebirth'' made it so it locks Mega Satan (at the time the TrueFinalBoss) behind Angel rooms (which may never appear [[LuckBasedMission if you were unlucky]]), and while all three expansions tried to rectify some of the problems by introducing some powerful items to the pool, they also introduced notorious {{Scrappy Weapon}}s[[labelnote:*]]Breath of Life, Dead Sea Scrolls, Glyph of Balance, Spear of Destiny and Trisagion being especially notorious[[/labelnote]]. ''Repentance'' gave a huge fix to Angel Rooms: changing or removing most of the no item layouts, massively buffing nearly every bad item in the pool (with Holy Water, Breath of Life and Glyph of Balance standing out more than most) adding tons of good/powerful items to the pool (be it old ones like Blood of the Martyr or new ones like [[GameBreaker Revelation]]), and making an Angel Room guaranteed on the next Angel/Devil Room spawn after you skip a Devil Room.

** Angel rooms are an alternative to Devil rooms first added in ''Wrath of the Lamb'' which in theory provide powerful items without having to pay health. The problem was twofold; first, Angel rooms cannot spawn until you've skipped a Devil deal at least once. That means you have to give up the huge power boost Devil rooms can provide going into the third floor to ''maybe'' get an Angel room next floor. The other, and more pressing, issue is Angel rooms were frequently ''awful''. There were multiple rooms that had no items, and even then many Angel items ranged from underwhelming to useless. There are standout great items, but it simply wasn't worth the risk. ''Rebirth'' made this even worse, locking the TrueFinalBoss behind Angel rooms which may never appear [[LuckBasedMission if you were unlucky]]. ''Repentance'' gave a huge fix to Angel rooms: changing or removing most of the no item layouts, massively buffing every bad Angel item, adding tonnes of new chase items to Angel rooms, and making an Angel room guaranteed on the next Angel/Devil spawn after you skip a Devil room.

* AudienceAlienatingPremise: The game could be considered one. You are a young boy named Isaac. Your mother was commanded by God to kill you to prove her loyalty, so you escape into the basement...which happens to be filled with demons, mutants, undead fetuses, and the occasional Horseman of the Apocalypse or incarnation of one of the Seven Deadly Sins. And you have to fight them off using only your tears. And sometimes your urine. Or your blood.
** Subverted in that it's done very well for itself, selling half a million copies, and the "Wrath of the lamb" expansion was in the top sellers list on Steam when it was released.

* JerkassWoobie: [[spoiler: As it turns out, [[BigBad Issac’s Mom]] is this. While her trying to kill Isaac is a figment of his imagination, she is still a very abusive woman who, depending on how [[UnreliableNarrator seriously]] we are meant to take the between floor transitions along with the definite abuse implications in some of the items and her Ascent dialogue, treated Isaac very poorly. However the revelation of her once happy marriage falling apart and descent into religious fundamentalism, along with her walking in on Isaac drawing her as a hideous monster, makes it difficult not to feel bad for her. This isn’t even getting into her own son committing suicide.]]

** The [[ResetButton Glowing Hour Glass]] has gained a reputation as being [[TheAllSolvingHammer the solution to literally everything]] (as it practically undoes any mistake you made in the last room), especially when it comes to several {{Game Brak|er}}ing GoodBadBugs that Glowing Hourglass is responsible for.

* WhatDoYouMeanItsNotForKids: The game is pretty gory, full of NauseaFuel and also takes a rather...shall we say, artistic license with the Biblical account of the actual binding of Isaac, which some may find offensive. It was reportedly rated M and for this reason.

* [[LowTierLetdown/TheBindingOfIsaac Low-Tier Letdown]]

* WereStillRelevantDammit: One of the items in ''Afterbirth†'' is [[VideoGame/PokemonGo Poke Go]]. By the time the expansion was released, while it still has a regular player base, ''Pokémon Go'' is largely regarded as a fad of 2016 by most people.