I'm with Archille on this one. I decided to accept the challenge at the end of the game and was rudely faced with getting killed sometimes faster than I could even activate a heal potion. I had to hope I didn't get poisoned if I wanted to make it through a stage.
Another thing I'd say would be worth adding is some walking speed boosting items, maybe not by a ton, but at least a little. I like being able to move quicker as a perk to getting farther in the game and getting rare loots. Also maybe items that increased attack speed, as well.
Otherwise, a pretty fun game! :) Reminiscent of the Diablo game style archetype.