Side Scroller Engine

Okay, I have been sick for about 3 weeks now and I am just now getting over it. So since I have been laying around and getting better, I have started working on many things. For example: Multiple engines for games, working on socket and multi user interface options in flash, random movies, etc.
I just thought I would post my side scrolling engine to see what people think about it. My friends and bro said they thought it was really good. But keep in mind two things:
1.) The first file had much more and was more detailed, but to large. So I adjusted it to fit kirupas upload limit by alot.
2.) This file will be updated alot, so there will be weapon pickups, ammo, etc.