This game is extremely visually pleasing and satisfying.
Just a note tho: F5 isn't really a nice key to press for webgl (when adjusting sounds)
Also maybe a sound fx for getting hit, and maybe a indicator for when the attack deals damage? (For example the first boss could have different colour for the beams of light when it's about to deal damage)
Other than that good job, can't wait for Whomst 3