Fun music! The gameplay reminds me of Hungry Knight which is cool; those devs did go on to make some pretty cool games :)
I wish the UI showed "missing hearts" so I could get a better idea of how much health I am losing; it is pretty hard to count them until you are already too low! Some sound effects for heart pickups would be good. Also, I wish the slash direction also considered the direction of the mouse and not just where the player was moving. The health countdown definitely feels too difficult to properly focus on combat.