The objective of the game is to finish all the levels by killing the guards. The best way to kill the guards is when they have their back turned on you. Try to time your attacks. Look out for traps.
The main strategy is to time your attacks. You can still kill them even after they see you by evading their attacks. Use stealth over assault. Good luck!
Jump, Move Left, Right Up, Left, Right arrow keys.
Attack A, S, D keys.