I liked "Champignons of the Spore-Pit vs The Roots of Industry," creative wordplay.
I just put down a bunch of the blue mushrooms and the enemies had no chance, easily got to 1000+ gold before I stopped. There didn't seem to be any reason to put down the red or pink ones, since the blue ones have such a large range. I know there isn't a lot of time in a jam for balancing, so it's tough to manage that.
The simple art is nice, pleasant to look at.