Submited a pre-final

Tomorrow probably I won't have time to submit, so I'll do it now. Many things are not implemented, so I might do a couple of things after pyweek, but it'l depend largely on some other work I need to finish

What I had to left out:
- Other kind of bad guys. Artwork is there and most of the code is.
- Destructible Floor and Roof. Artwork is there, most of the code is there except for the dynamic generation and reflection
- Boss. Nothing is done. The idea would be to have a big switch behind him, and having to hit it with a deflected bullet to turn the AI off

-Better collision/deflection. It's mostly there, but having the y axis inverted and some other minor problems had taken up most of my time.

If I have some time tomorrow (which I doubt) I'll try to put up the destructible walls.

Overall I'm satisfied, first time with pygame and in a tough week and I got something playable. We'll see what happens next pyweek :)