Here is the full list of all 20 Commander Cool 2 achievements.
Kill 10 enemies
Die 100 times
Play story with 2 players
Start the first stone age Level
Die 10 times
Complete all stone age levels
Complete all stone age missions
Collect all stone age diamonds
Kill the boss in level 5
Survive level 10
Beat level 15
Kill 1000 enemies
Collect 100.000 coins
Die 1000 times
Kill 100 enemies
Collect 1000 coins
Collect 10.000 Coins
Escape the T-Rex in level 20
Kill the boss in level 25
Kill the final stone age boss