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