Here is the full list of all 40 Desktop Cube-Man achievements.
Use gatlin
Complete Challenge 13
Reach Level 15
Complete Challenge 12
Reach Level 14
Reach Level 13
Reach Level 12
Reach Level 11
Reach Level 10
Reach Level 9
Reach Level 8
Complete Challenge 11
Use automatic rifle
Reach Level 7
Use shotgun
Use handgun
Reach Level 1
Reach Level 2
Reach Level 3
Reach Level 4
Reach Level 5
Reach Level 6
Change to new action type
Complete Challenge 10
Complete Challenge 9
Complete Challenge 8
Complete Challenge 7
Play challenge mode with friends and survive 60s
Complete Challenge 6
Complete Challenge 5
Open the chat window
Complete Challenge 4
Complete Challenge 3
Complete Challenge 2
Complete Challenge 1
Play challenge mode alone and survive 60s
Start challenge mode
Open the about window
Complete Challenge 14
Complete Challenge 15