Here is the full list of all 23 Afterparty achievements.
Beat Satan and earn your way back home.
Make friends with Sam.
Make friends with Wormhorn.
Reunite Milo and Lola.
Intentionally curse twenty times.
Play as Milo after fighting with Lola.
Get Asmodeus's Seal of Approval.
Get Apollyon's Seal of Approval.
Play a perfect stacking game.
Try 20 different drink types.
Waste 20 minutes on Bicker.
Pet the damn dog.
Get an Invite to Satan's from Fela.
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.
Drink a lot of booze.