Excellent high concept! Didn't really translate into gameplay though.
Intro is cool. Nice that you got a fairly high level of completion art- and gameplay-wise!
Gameplay I didn't feel was all that compelling. Walk back and forth, shoot, repair. Not much to it. Obviously you don't have buckets of time here to make something advanced, but I'm not sure where you'd go next with it -- you could turn it into a kind of tower defence kind of thing, but it would take a pretty major overhaul to make it interesting.
Still, good work :)