This is pretty well done! The graphics are great, the music is really nice too. The people you got to talk to near the beginning were fun. Exploring was fun too, although after a point it was like "ANOTHER room?". (And, I don't know if anyone else has this problem, but in the very beginning it took me a while to figure out that I had to jump into the...teleporter, I guess?)
I'll have to echo what everyone is saying about the jetpack; you have to jump twice with one hand, then control your movement with the other hand. So you are sort of mentally switching between states, and it's a bit confusing...Especially when you accidentally land on a platform and you realize that moving WASD is not making you fly around any more! I guess the point I'm getting that is that there are two modes of movement that you switch between, and it's hard to keep track of that. And on top of that, the weapon is kind of nonstandard and tricky to operate...which is not necessarily bad, but...
Anyway, you obviously did a lot of work already, I think it could become something pretty special if you polish it some more!