Definitely a very interesting way to setup a chaotic game. There's some nice variation in how the game can be played, weighing the risk vs reward on what the enemies, how many points you can make etc.. The idea of a map layout with abilities and such is interesting, though I do feel like the health was a bit of a weirdly handled addition. Not giving a max to it and essentially having it stand in for lives.
One issue I would say though is that the abilities were a bit underwhelming, except maybe the invincibility, except that ones pretty nerfed by the amount of enemies that will likely be shooting all at different times with such a small window. I feel like a longer window for the invincibility would be good to counter that, since it would give it more variety, possibly having it cancel another ability could work.
That would counteract the spamming of space depending on what ability you had. Since being invincible, attacking and firing projectiles is a pretty endless combo. Assuming invincibility is worth it obviously, which at the moment it really isn't in my opinion, but that does fit closer to the idea of being able to have all the abilities at once at least.
Overall the only thing I'd say is that having such a curated level and then making it a flat high score game is a bit weird for one of these. I personally would've preferred multiple levels with their own goals/settings that limit the spread, though I may have just missed them since I didn't manage to beat too many.