Thank you for the feedback!
I also feel that the gameplay's not really locked into an effective groove. There are elements of the mechanics and design that I'm happy with, but it's not particularly cohesive. Platformers that really emphasize melee combat tend to have a pretty different feeling to them, I think - castlevania-style games (as an example) are much more grounded, attacks are (generally) longer reaching and more committal, etc.
I was interested in this game having a different focus - more emphasis on finding the right moment to strike so you could move through damaged enemies and get through safely, not so much focus on sustained combat. Under this idea, enemy health is most impactful in determining how many times you might have to interact with an enemy before leaving it in the dust (or bubbles, I guess) but rushing ahead presents dangers. Especially when *somebody* (it was me) made crabs explode out of every nook and cranny of the level.
So yeah, I don't think the ideas necessarily came across the best, but I think there's a workable idea here that's focused on making movement through and around enemies fluid and fun.
Thanks again, I appreciate you taking the time to give feedback. Thanks especially for noting the things that didn't work for you. New ideas and different perspectives will help us make stronger games.