I really like the Shroom theme. I saw the thumbnail, and was like immediately~ Shrooms!! XD Then you start playing and the music hits (though it was way too loud with the types of instruments and bizarre sounds)~ I liked the vibes.
I think it is interesting the way you have the ability tree connected at the bottom as the mushroom network, like the true nature that would be. That is an interesting way to have your towers and abilities interacting. The visual theme is well executed overall for the story. The sound effects kinda don't make sense, but it is what it is. I wish there was more feedback and more clarity that can tell you what is going on with your towers. You don't know anything about the towers other than the way they look (no damage type, damage range, dps). You kind have to guess all this information.
It is hard to tell when and if you are selecting anything at all, from the tower positions or even on the abilities in the network. Some of the times I was just clicking to see what changed. This game needs some tooltips when hovering over all these different things!! I don't even know I am spending points unless they are gone and I am not longer able to just randomly click on things. You should consider confirmation menus that are like yes or no prompts before following through and committing with changes and or upgrades before the nutrition is consumed (also gives the player a better understanding of what they are affecting). I could even see some kind of menu that you can pull up as a log that displays all the bonuses you have acquired within the network. You should also consider some visual feedback to show the gain and loss of nutritious.
I would also use different sound effects for different enemy types when they are destroyed so you can memorize which enemies you learn have been killed, especially since you are likely not going to see them dying, but only hear all their sound effects. But at least in this way, if you do happen to see when that particular enemy dies then you can associate the sound effect, you have a better relativity. If you are going to be keeping the level this long and spannable horizontally, I would consider creating a space beneath the mycelium network that acts as a mini-map that shows the entirety of the level and then visual indicators to represent the enemies, and at least this way if you are not panning around, you still have a good sense of the enemy waves and the distance and location of those enemies as you focus on the center point of the overall game space.
#Boomerang Mushroom... lol~ yessss
The Connection theme is perfect for mushrooms and the mycelium network
This game would be really great with more time invested in it!! It already has a solid foundation of what it wants to do! I would come back to player this tower defense after it has some more clarity in the gameplay : )