This is absolutely amazing. The gameplay and level design are incredibly fun, and I loved the art and music. The ability to change the color palette on the fly is a nice touch, too.
The only thing that felt off was the fact that sometimes I had to move in a certain direction, while shooting a star in the opposite direction, which was a bit difficult. I was playing with a keyboard, but maybe it's different with a gamepad.
I completed all 16 levels (minus the challenges at the end), usually with a 2-star rank. I noticed that everything was in English, but if I hit Esc to bring up the pause menu, it was in a different language. This only occurred during the challenge levels at the end, for some reason.
Very well done, and I cannot wait to see more of this.