I really want to like this game because I liked the idea, but the execution is just terrible.
You either forgot to randomize level generation, or this game has some really bad level design. And even with random levels you should probably do something to prevent the biggest flaws, like spawnkills (That's an easy fix, just make the player press space before every level, not just the first), and put some difficulty progression aswell, You can't go with a hard level right from the start.
On the other hand art was pretty nice (Even though it's not cohesive at all), I liked how you could swap palettes, and the sound got kinda repetitive after a while, but you had sliders for that too, so good job.
Gameplay was kinda meh, some parts were really unfair, but it was still fun for the majority of the time.