I really like it! I think because the mechanics themselves are easy to understand, it's possible to just play a few rounds on a whim, but since the game is pretty unforgiving (at least to me, current high score is still 501, rip), it doesn't get boring and just makes me want to try over and over again.
I like the movement of the enemies, I think it's kinda fun and stimulating. My tactic is to stay in the lower section of the screen so they don't trigger their attack with the red bullets.
The artstyle is very coherent and polished! The music is cool, and aids concentration.