Keeping this going for 31 levels, much less 1001... just seems crazy.
I like the design, but the level layout/enemy count feels a bit too compact for comfort. You're boxed in almost right from the start, new enemies keep popping up, and there's no margin of error at all if you want to survive... maybe it's a game you can master but first impression's difficulty is just way too high.
Thinking a few lives and/or power-up's to assist you might boost the concept, or just a larger canvas, so you can keep track of enemies more from afar. Or both.
-cd-