This was really really fun! I liked how much I had to balance, it was just the right amount of concepts to juggle without feeling overwhelming. I think the fact that all I had to do was spin wheels, cast spells, and place towers made it work well; anything more complex or required more brainpower would burn me out. I got so into spinning the wheel to unlock more towers, my girlfriend was laughing at how intensely I was moving my arm in circles xD
I think I made it about 4 minutes after the tutorial. Very likely was my fault; I front-loaded the first loop in the path with tons of weapons, mostly ignored the latter half, and I think forgot about the enemy wheel. So the difficulty is probably fine, but maybe an easy mode or multiple levels would be nice to have if you continue working on this. Great jam game!