Nice work! Love the way your gun is both a means to kill enemies and get around. I like the levels you setup as well!
There is a bug with the first level I noticed where because it includes the intro and the sound track playing, if you do run out of time on this level it will cause the music to start playing again without stopping the last set of music.
I tried again from page refresh and if I got past the first level and ran out of time it was fine
Other than that nice job!