This is one of the best games I've tried so far. The art is incredible, it has a truly professional feel to it. I beat all 3 bosses, they're unique, fun and challenging, but don't feel unfair. The controls felt mostly good, except for a couple of points, if I could add a bit of feedback, it'd be:
I feel this game could benefit from a sort of auto-lock feature. You could maybe add a button to toggle between having the boss locked as a target or not, and while your movement would be the same, when you have the boss locked your character would attack/parry towards the boss, it would help make it feel a bit smoother. Especially the parrying, which felt a bit awkward at times.
Also, I saw you added shockwaves during the healing animation to stop the character from taking damage, I'd say you could make that last a fraction of a second longer than the animation. That way you don't get hit by attacks right as you finish healing. With the 2nd boss arrows, if I didn't spam dodge after parrying an arrow, most of the time I'd get hit by an arrow right as I left the healing animation.
Overall, it's an amazing game, one of the best I've tried so far, great job!