I'm really bad at this game but it was fun to play! :D
some seconds of invulnerability when you spawn could be cool, sometimes i would spawn and insta-die because a random bullet happened to be there already. also something to make them more visible would help.
the graphics, specially the background look really good!
the game just stops when you are at -1 lives and the music keeps playing, not sure if that is intended or it just "end game" and i didn't wait enough.