Good start! My two main criticisms right now are the blocky resolution and the handling. Oh, and it could do with preloading the assets better (it kind of just freezes while loading things, and then is stuttery for the first explosion I presume because it has to do a fetch.
The resolution is just too blocky to see the ships coming at you before they are right in your face, so you can't hope to try and judge their velocities to try and lead shots etc.
The handling is OK, but I think I'd prefer it if the top speed were a little faster, at least in this arena.
The shooting and explosions are pretty good.