Very cool game! I tried and tried again, pretty hard but consistent in its difficulty! I guess you could define this a "2D Dark Souls" x)
My suggestion is to allow defending to cancel your attacks. Often, I clicked on attack but regretted it, and there's no way to stop the animation... I don't know if it's clear what I'm saying, it's just that it felt like some deaths were not my fault because "the game didn't pick up the input in time"
Since guarding at the right moment allows to parry, and that you can still be hit when guarding, it would simply remove the game's "artificial" difficulty, and make it less frustrating to play over and over.
Also, great graphics and great audio! Really polished :)