interesting game. though i early found that you can cheese heal the mage to full health when the only enemy left is a power up, or another weapon. got to level 12, and didnt really see anything different. this could be a interesting clicker game if changed a bit. maybe add some spells for the mage, instead of the mage using swords and axes and things

I got to about level 10 (Paladin), but got a streak of swords and no healing potions, and died a heroic death fighting skeletons... Are there any new enemies after skeletons and shamans?

This game is fun to play for several minutes, but then it gets repetitive. I think you need either some overarching plot / quests, or achievements to make it more addictive.

Interface-wise, I have a bit of an issue with having to drag potions to the inventory, then into my hand, then onto my character - I understand that this is needed because of limited inventory, but it's rather tedious to perform a hundred times :)

Nice work! I like the concept of card game roguelikes, and I'm happy to see this here.
I like the bits of polish in the UI, like the way the cards animate and the drawing of the arrow.

I agree with Eldar's comments - it's a little unintuitive taking in items and managing inventory, and I might have preferred something simpler like an automatic "pick up" button for example. Grats on your submission!