Very well made, I could see this being a full game with more content.
Though more uses for the money would make sense, like buying more charm space. As by round 5 I had max charms and hundreds of dollars with nothing to spend it on.
Also make it so the new enemy spawns faster if none are alive; By the end I would kill an enemy nearly instantly and then have to wait ages before the next one.
And maybe reduce the trip chance; half of my charms where the 'New Boots' to reduce it by overall 60% and I still tripped fairly often.