I enjoyed this small game.
I think the players bullets are too slow. Its weird to be able to outrun my own bullets.
Also one thing that could maybe be solved by taking the camera back a little is that there were times where as soon as I would notice an enemy or a bullet at the edge of the screen it would kill me.
The game felt like it was harder than it was supposed to be because of some of these design decisions. If you want to make a good game you have to keep in mind that often what makes a hard game good is that you feel like losing was your fault and you can do better.
I loved the visuals and the music was good.
Good one!