This looks pretty good overall. I think the cockpit could probably use a single pixel outline around the back of it. Basically just the outline color you used for the rest of the ship just needs to wrap around the back of the cockpit to make it more distinct.
It doesn't really need a background though, even if it matches the default background of this site. If you aren't sure how to make a gif transparent, here's a helpful guide in our forums- link
Thanks a lot for the criticism, I'll take your advice and resubmit :)