A very cool concept. I really like sort of scurrying under the hero's feet and giving him stuff, and picking up the remains. I would have liked to see some more interaction between the sidekick and the enemies; I'm assuming it was planned but you ran out of time? Because I see there's a healthbar on the side, which I assume is the sidekick's?
The difference in style between the hero and the sidekick was a bit strange looking, but both are nice in their own right. Also, most of the time, the hero sort of just hangs out at the last entrance he was at. Maybe he could walk back in so the fighting isn't so isolated to the edges? And/or make him walk slower?
I liked that the potions were made of stuff you picked up (though maybe recipes in the table would have been nice?), and that upgrades could be bought (though it was annoying to go into upgrades, see you can't afford anything, and then be forced to go to the next wave, rather than being able to rest instead). However, the hero very quickly became an unstoppable killing machine. Cool game.