Only since you asked :)
I'll piggy back on what Cinetic said about visual feedback for my game. The vibes of your game are immaculate and I like the idea of growing the flowers to attack the spiders. Adding in some type of indicator to say how damaged the spiders are would make the flower damage seem more impactful. Adding in a way to change which flower you plant and giving them different levels of damage or abilities could be cool too. So yeah, just adding more "juice" to the combat. 

Bonus tip from a noob.
Super simple tweak: Just in case it isn't something you know, you could mess around with the tiling dimensions on the ground texture to make it look less tiled.