A nice little bop of a game. I feel like this kind of game lives or dies on how it feels to control and how readable it is, and this succeeds on both fronts.
My one complaint is that I had a hard time parsing the health mechanic. I thought it was instant death, but was confused why my score didn't seem to reset. I think that's partly because the health bar isn't super obvious, combined with the game essentially resetting on a hit. A piece of VFX showing why the enemies are being destroyed might be a nice extra touch (like the bomb in geometry wars)?