Preset cool so far. I agree with wazk, some sort of high score would be good. It would be a fun way to keep users engaged.. You can make it so when you lose it says your current score, and the previous best score. That way the player knows how far off they were.

The game is fun in its self but there a few things to improve. Like to chose your knife it just makes a click noise there should be something the says your knife has been chosen. You chould do once you chose a knife it moves to the main menu and the knife but now is the knife you chosen. And on another note of knifes right now there is no goal there is to make a high score but it chould be better if you made it make points to buy knife that whould be cool.