Excellent Work!!
One of the Visually Best I've seen on Newgrounds. The previous reviewer is whacked on a few points, however.
1. Yes, you possibly could have used better sounds, However the ones you do have are Excellent.
2. Focusing on the story is never a bad thing, and Shields and Bigger Guns only fit if there are supposed to be bigger guns availiable for the spaceraft's Technology and Design
3. Bah what do you know, can never please everyone, nebula is fine, better then empty space.
4. You can have fire in space, it just burns quickly and is fueled by the oxygen in the lifesupprt systems, and other reactants in the fuel systems. Explosions in space do have a uniqe shape, however they are sphereical in shape without exception, no gravity to distort the expansion patterns
5. the fire effects may want refinement, but it is still a lot better then 90% of the attempts out there
KEEP IT UP i'LL BE LOOKING FOR THE NEXT ONE :D