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