A really neat and pretty game! Loved playing it.
Unfortunately there seems to be a bug that sometimes fails to transition to the "build phase" after a wave is cleared, softlocking the game and forcing a restart. Happened to me twice.
Also, it seems that just spamming AoE mushrooms and walls to guide mobs around them is a fool-proof way to win every stage. Once you build enough AoE towers to kill the toughest enemies (snails), nothing can pass your maze, no matter how many enemies are in the wave. I suggest making a boss after the last wave to counteract this tactic. Or maybe make an enemy type that is highly resistant to AoE.