Here is the full list of all 13 CPU Invaders achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Destroy 5000 Invaders.
Destroy 1000 Invaders.
Destroy 3000 Invaders.
Clear level 10.
Clear level 9.
Clear level 8.
Clear level 7.
Clear level 6.
Clear level 5.
Clear level 4.
Clear level 3.
Clear level 2.
Clear level 1.