I like everything except the laser beams and the explosions they make. They look composited and not part of the same image. they are too soft with too much transparency perhaps, especially the explosions. But if that was just to get an idea of the position or the scene in general nm my comments.

Maybe use a transparency map to give some transparency to the edges leaving the middle of the beams solid. Or use a glow effect or something like that. Im sure you'll come up with something.

good work!