Here is the full list of all 28 Aplowcalypse achievements.
Look at the credits
Score 0 points
Play 42 Games (any mode)
Beat the Story
Beat the Story without losing a life
Beat the Story with 4 players
Play all 3 game modes (Story, Score Attack, Survival)
Do you wanna kill a snowman?
Score 1,000,000 points with 2 or more players
Hit 3 players with a single Knockback
Never use plowerups in a single game
Never kill another player during a 4 player game
Score 1,000,000 points
Get killed by your own fire tire
Score 500,000 points in a single bank
Steal 500,000 points from another player
Snipe a player with the High Beams from across the map
Listen to the full menu song
Win by 100,000 points in a 4 player game
Steal from all 3 other players in a single game
Kill 2 players with a single Gravity Mine
Discover a worm hole
Play a 4 player game
Never use your boost during a single game
Survive for 8:15 in Survival Mode
No hope for mankind
Thanks for "playing"
Never use your secondary during a single game