Very fun game! The idea is solid, the upgrade system is very cool and fitting, the artstyle is cool and charming, audio is pleasant. The base is solid and I see that many cool features can be added on top, for example something like moving plants to another spot to save them from an incoming flood would spice the game up without simply increasing enemies' health.
However I think the game needs some balancing. It doesn't really scale all that well later in the game, and when by the wave 19 I had about half an hour time left, I didn't feel like playing further. Maybe more things, that you have to keep track of will make the late game more interesting.
But I liked playing it, so good job!
