This was an interesting concept.
At first I did not understand because I was clicking too close to my little center point instead of outward towards the trees. I think it is easy to misjudge how far away you will be able to click in order for the line to start growing out to that click point. I actually locked myself out from being able to play at first because I didn't click any trees right away. I clicked around my center point and because I didn't see anything immediately happening, all my energy got used up by the time I noticed my little paths had grown out to the small distances. There should be some kind of visual distance check that let's the player know how far they have to be away from a potential point to click on as a viable option, in order for the path to start to grow where clicked. Also you don't really know where a branch will grow from and how or which path it will take to make a connection (it's not obvious... which isn't too damaging for you if you are generating energy infinitely, you can't really run out of guess and check options).
The prompt that you have at the top right of the screen may not be immediately noticeable as something you should be paying attention to, even though you would think it's obvious. I feel like you should change the text prompts to an on click implementation, so you can be sure it get reads (if this is how you continue to provide your text information to the player). If you happen to not be paying attention when you start because you happen to be clicking the game space, you may miss one of those texts because it has moved on to the next text sequence.
Possibly consider blocking the gameplay functionality until after the player has read the prompts if you are not going to do a tutorial.
Consider changing that Energy Bar graphic from being 1/3 dark pink. My eyes were very convinced that for some reason it was a time bar and I swear it was counting down (because it was moving when it wasn't~ just my own hallucinations because of the colors and the fluctuating energy values). The pink and the yellow are a lot together (on the eyes). Also I feel like if you color the Buttons and UI to fit the same colors style as the game's Main Screen, it would be a Chef's Kiss.
It's kind of strange to me that this a luck based mechanics as 50/50. Maybe consider implementing some kind of system or something engaging for the player that can change these values where something that is threatening in the game lowers the percentage and then something that grows the percentage in your favor (if you keep the game luck / percentage based).
I really liked the thumbnail for the game, which is what lured me in. I like the Lofi music... something about it does have a fungus growth vibe XD I feel like if you were able to develop this game's art assets around the same way the thumbnail has been designed, it would be very charming and engaging in its own way. It would be so flavorful.
The theme CONNECTION is here, given the mycelium. Needs more Kingdom :P
The game could also use a navigation menu which I'm sure you know, if you continue to work on the project. Currently I just have to reload or close out of the browser completely to end that game.
Would be interesting to see where this project goes : )