Thank you very much for your feedback. I haven't had time to adjust the difficulty balance, and I understand that the design may have become too punishing (problems of making a game jam game alone). The mechanic for climbing the ledge uses an upward tap because the jump button is then used against the wall for the wall jump, and it was causing a conflict.
After making a separate button on the gamepad to activate the parry along with the defense, I plan to do the same on the keyboard by removing the upward button. In fact, the enemies that shoot fire from the spikes are better countered when you use the Parry to deflect their shots before advancing, and if you can't use the ability, you'll have more difficulty. I particularly like using the downstab (down and attack in the air) to bounce off them, but it can also be difficult to do. I plan to apply a secret item that negates knockback, but this and other adjustments will only be made after the game jam voting is over.
Thank you so much for your interest in the game and for your honest feedback. I will consider what can be done to make the game less punishing and more fun. I hope that next time you will be able to enjoy the game after the changes.