Here is the full list of all 14 Pikuniku achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Kick Mr. Sunshine into space
Collected 70 coins
Finish a coop level in less than 3 minutes
Kick your friends 50 times during a single level
Found every insect
100% against the dance king
No respect for Sam's potteries
Found every trophy
Get some arms
Escaped from Toastopia
3 baskick wins in a row
3 baskick loss in a row
Make an artistic statement
999