Here is the full list of all 16 Space Impact Glitch achievements.
Kill 4 enemies simultaneously
Complete first level
Start a game
Run a new version of the game
Do not receive damage when passing level 2
Complete 9 levels
Pass the whole game
Press the mute button 400 times
Play the game for five hours straight
Kill 256 enemies with your shield
Pass the 9th level without taking any damage
Use 50 aid kits
Die 50 times
Ram 50 copters
Get 30 or more HP
Destroy 3 Walls