Things I didn't like: Music occasionally went out of sync, I experienced the same bug as @SMAEL where it skipped straight to being able to attack and dash, falling in holes felt rather punishing especially as dash gets a bit weird around walls.
Things I liked: Dash and attacking felt really good and the difficulty of using them (partly due to the delay and long animation) made them very satisfying to learn and use correctly. Difficulty is also pretty much on point. Boss in particular was wonderful. And yeah, your art is some of the best here.
Overall I thoroughly enjoyed my time with this game, great work guys!