I liked the main gimmick. Having to hit the enemies in order to regain health reminds me a lot of the Bloodborn rally system encouraging aggression by making it the only reasonable way that you'll survive. Honestly after a bit I started to dig the sheer chaos of the bullet patterns because it gave a feeling that you're going to be taking damage regardless of how good you can dodge, so you have to be constantly damaging enemies in order to compensate for all of the garunteed damage you would be taking. I think it's simply engaging to have the aggressiveness be the primary focus while you can work on dodging after you get good at it.