Interesting concept! I think this idea has a really good framework that could be expanded into something greater. Firstly, some extra sound effects when you get hit would be nice. Secondly, whilst I like the really powerful attack that hits in all directions, sometimes the feedback on it feels really inconsistent because there seems to be a delay between when you can attack again? Also it doesn't feel like there's any invulnerability period when you get hit, which made the fast slime-like creatures almost always end my run as multiple would dash into me at the same time, bringing me down to 1 or 0 hearts :(

I think having some way to offset the total futility of having no control when you are on 1 heart would be good to allow the player to more reliability clutch the situation and rebuild their hearts (e.g. some kind of buffed "last stand mode" when you are on 1 heart for 10 seconds) so being hit doesn't instantly cause the cascading total demise of a run?

Perhaps some way to be able to hot swap your abilities around so you can priorities which abilities you would sacrifice? Or maybe a "shield" ability that takes 2 hits to lose that heart? You can really expand this in a lot of ways! :)

Very interesting concept -  I like the idea of losing/gaining new abilities/skills alongside your health and it could work well in more of a roguelike style game. If you were to take it further, it would be pretty cool if perhaps instead of losing abilities as you lose health, maybe you could gain some as well, so you can avoid the whole domino effect where losing one health/abilities makes the game harder.