Here is the full list of all 15 Keyboard Killers achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Quit the game
Click Backspace
Click MainMenu
Click Pause
Click Undo
Click End
Click Tutorial
Change Music Vol
666 KILLS
9999 KILLS
25000 KILLS
100000 KILLS
Click Enter
Accuracy 100%
Kill 1111 meteors in 1 lvl