I noticed that depending on the amount of mushrooms in stump, some groups of 5 or 10 were represented by a single mushroom attacking. Although that single mushroom still did 5 points worth of 'damages' those 5point shrooms seemed to be as susceptible to gunshots and attacks from "mushroom towers" as 1point shrooms.
perhaps this is worth addressing,
So the towers have a small amount of life points, and no attaking when his life below 5
It's fun, but really easy.
Here's the thing: The player is smarter than the AI you're using. To challenge the player you'll need to give him levels that are actually unfair, where the enemy has a distinct advantage. You have some elements of that in there, but not enough.
For the rest it's pretty good, it's a nice variation on the theme. A bit standard perhaps.
Advertisement Appeared during game play and wouldn't disappear. Refreshing the page was the only solution; doing so also restarted the entire game. Very good game though and addictive.
But I never played an easier game of this genre, I feel like the red mushrooms are much stronger than the others.