Here is the full list of all 31 The Adventure Pals achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Kill an enemy that's been converted to a bunny
Use the Cupcake Converter
Complete your first objective
Collect 10 cupcakes
giraffe-copter for 5 minutes in total
Level up your abilities for the first time
Vanquish 10 enemies
Collect first cupcake
Get your first pal
start a co-op game
Make it to second island
You've used nine lives but don't give up
Use a Weapon Mod
Kill 20 yaks on world map
Defeat treefist
Defeat Breakfast Buccaneer
Defeat Veggiesaur
Defeat Crab mech
Defeat Hot Dog Boss
complete a stage in less than 3 minutes
Give the whale the old mans underwear
Release 50 old people from hotdogs
Defeat all the arenas
Find 50% of the stickers
Beat an arena
kill 100 enemies by jumping on their heads
Fill up your sticker book
Get all achievements
Unlock all costumes
Fully Level Up
Finish the Game