I like the star background. I also notice the monsters are always lower on the left when they spawn in. The controls were odd at first, I had to look them up, as I expected Space to be shoot.
thanks for trying it! that's because i spawn them from left to right, adding a random Y to each one, but the first ones are almost always on the down side for the controls i totally forgot to write that on the description, now they writen there :D