Here is the full list of all 23 Afterparty achievements.
Play a perfect stacking game.
Get an Invite to Satan's from Lynda.
Drink a lot of booze.
Beat Satan and earn your way back home.
Make friends with Sam.
Make friends with Wormhorn.
Reunite Milo and Lola.
Waste 20 minutes on Bicker.
Play as Milo after fighting with Lola.
Intentionally curse twenty times.
Get Asmodeus's Seal of Approval.
Don't miss a step while dancing.
Get Apollyon's Seal of Approval.
Try 20 different drink types.
Pet the damn dog.
Get an Invite to Satan's from Fela.
Kick off your adventure in Hell.
Play as Lola after fighting with Milo.
Intentionally lose to Satan.
Fail to beat Satan.
Recruit the Drunk Idiot Demon for Satan's final challenge.
Reunite Beth and Asmodeus.
Play a perfect game of beer pong.