Here is the full list of all 27 SOYF: S#!T ON YOUR FRIENDS achievements.
You played SOYF at least once, impressive!
Friends who poop together, stay together.
Squeeze out 1337 poops.
Land 420 poojectile deflections.
Complete a game of Dinglebrawl.
Complete a game of Training.
Complete a game of 1 S#!T Kill.
Win a match as Isaac!
Win a match as Dookie!
Win a match as Greg!
Win a match as Puglie!
Play a Dinglebrawl match that lasts longer than 120 seconds.
Finish a Classic match in less than 30 seconds.
Win a Classic game without being hit once.
Win a Dinglebrawl match without being hit once.
Get a total of 100 bank (bounce) shot kills.
Beat the training on Dank Caves in less than 15 seconds.
Beat the training on Mean Greens in less than 15 seconds.
Beat the training on Snowdown in less than 15 seconds.
Beat the training on Candyland in less than 15 seconds.
Beat the training on Basement in less than 15 seconds.
Beat the training on Heatwave in less than 15 seconds.
Beat the training on High Tide in less than 15 seconds.
Beat the training on Pootcamp in less than 15 seconds.
Get a kill while affected by each powerup.
Win a match as Fish!
Beat the training on Spoopy Woods in less than 15 seconds.