History YMMV / TheBindingOfIsaacAntibirth

** Magic Skin uses up a Heart Container to generate items. The heart is replaced by a broken heart that cannot be replaced by other pickups, essentially lowering your maximum health. However,if you play as [[OneHitPointWonder The Lost]], you can use Magic Skin to get '''every single item''' in the entire game, as he cannot gain broken hearts due to a lack of health.

* AntiClimaxBoss: While [[spoiler:The Witness]], the final boss of the Alternate Route, is undeniably [[AwesomeBosses/VideoGames an awesome boss]], it lacks one thing that the {{true final boss}}es from ''Afterbirth'' and ''Afterbirth+'' had: [[DamageSpongeBoss scaling damage resistance]], making him more of a [[GlassCannon glass cannon]] compared to other final bosses. Because of this, it's possible to steamroll through it with the right items; for example, a familiar that can home in on and attack enemies, like a Level 3 or 4 Meat Boy. Worse, if you managed to even get to it in the first place, chances are you're powerful enough to just stamp through, so steamrolls are more likely than a true ClimaxBoss fight. The fight was made much more impressive in Repentance by making the arena much smaller and giving the boss damage scaling.

* DifficultySpike: The alternate chapters introduced by the mod are ''much'' harder than their counterparts in the base game. This comes with the reward of item rooms always having two items to pick from. The bosses are a big step up from the base game, since most of them engage in intense bullet hell or have fast attacks. Which is why in ''Repentance'', the alternate floor requires defeating '''HUSH''' 3 times.

** The Rainmaker, the flamenco-dancing, water-bending poltergeist boss, earned quite a few fans for his quirkiness. Being adorable also helps. He's so likable, [[WordOfGod Edmund]] said he wanted to cut him from ''Repentance'' for not fitting the Isaac universe [[https://twitter.com/edmundmcmillen/status/1321662651055796224 but couldn't bring himself to do it.]]

** Rock Bottom. Having it prevents any of your stats from being lowered, allowing for items like Ipecac or Soy Milk to be a lot more powerful than usual if picked up in the right order - which leads to complete game breaks if any tear modifying item is picked up after Ipecac is due to not losing the +40 damage increase.
* GeniusBonus: Like the orignal Isaac, this mod is full of this:

* HilariousInHindsight: About a year after ''Antibirth'' released its "two characters in one" package of Jacob and Esau, ''The Binding of Isaac: Afterbirth+''’s final official update included its own "two characters in one" package in the form of The Forgotten and The Soul. The major difference is that Jacob and Esau requires controlling both characters simultaneously and both differ from the rest of the cast primarily in terms of stats, while The Forgotten and The Soul function more like a TagTeam and have individual quirks that make them much more different from other characters even beyond the "two in one" aspect.

* AntiClimaxBoss: While [[spoiler:The Witness]], the final boss of the Alternate Route, is undeniably [[AwesomeBosses/VideoGames an awesome boss]], it lacks one thing that the {{true final boss}}es from ''Afterbirth'' and ''Afterbirth+'' had: [[DamageSpongeBoss scaling damage resistance]], making him more of a [[GlassCannon glass cannon]] compared to other final bosses. Because of this, it's possible to steamroll through it with the right items; for example, a familiar that can home in on and attack enemies, like a Level 3 or 4 Meat Boy. Worse, if you managed to even get to it in the first place, chances are you're powerful enough to just stamp through, so steamrolls are more likely than a true ClimaxBoss fight.

* UnintentionallyUnwinnable: When you defeat [[spoiler: The Witnesses second form of a floating head]] it turns to stone and falls to the ground, if it happens to be at the center of the room, it will block all access to the chest that ends the run, however it can be saved several ways, either a teleport item which will despawn the boss dead body when you reenter or just quit and reload.

* UnwinnableByMistake: When you defeat [[spoiler: The Witnesses second form of a floating head]] it turns to stone and falls to the ground, if it happens to be at the center of the room, it will block all access to the chest that ends the run, however it can be saved several ways, either a teleport item which will despawn the boss dead body when you reenter or just quit and reload.

* SugarWiki/AwesomeMusic: The mod has all [[https://www.youtube.com/watch?v=c5gejcfpr1w&list=PLkpGvIpK1f3r6yTChZtlzn-kj5uWHS77v original music]], even for the vanilla floors, and they are all of professional quality.