Thanks for your feedback, glad you liked it!
I saw this bug in the last hour of submission, it occurs when the player and the enemy can't take damage with simple attacks, only with critical attacks, then my idea to solve that quickly was to increase the critical attack of the player and the enemy, but I didn't have time to test. I probably did something wrong xD
About the art, I didn't look very much to it, but if I continue the game I will definitely improve it.
And about the heads up display, I intend to add other visual effects to show whats going on in the battle.
I just played ant rated your game, although I'm not very good in metroidvanias, I liked very much, the jogability is very nice and the art fits very well!