Really fun game! Reminds me a bit of Desktop Dungeon :D
Only 'issue' I found is that if I press the move key in specific direction a milisecond too long the player character jumps across the screen until he hits enemy or the wall, but it might as well be considered a feature xD Corridors are often long so its hard not to be tempted to press that button a bit longer :) Stats of the weapons after upgrading also seemed to be not changing to me - would be cool to display in what way the stats of the sword or boots upgrade when you spend xp points.
Other than that - it's a really engaging game, simple in controls (which is good), but quite complex with all the options and variations of items and enemies! Great job!