Nifty little game you got here. I works great. Very smooth. The music is nicely chosen and so are the sound effects. I'm not so keen about using the same button for two different functions though. I often pressed the spacebar longer than the specified 2 seconds in order to release a bomb (which btw is the most fun weapon to use by far), only to find myself destroyed because I waited too long. Which brings up the matter of replaying the game. You need to restart the whole program in order to do that. It kills your flow. Other than that, nice job!