A good start.
This game has potential to be awesome. It only needs a couple of things.
1. A bit catchier music
2. More instructions (I found many couldn't think of picking up the gun, so maybe have a red arrow pointing to it and saying 'get the gun!'
3. The only glitch I have come by, (only the first level) but it is basically game ruining, seems to be the man cutting through the floor. I'm not exactly sure why, but he fails to fire the rockets that he successfully fired the first and second times I played. Instead, a little explosion appears above his head, and he cannot die.
Fix all of the above and we're getting somewhere. :3