Great game concept, this could def be a pretty popular game with a bit more polish. I'd suggest making it a bit quicker to get automation setup, maybe add +0.5 Energy per second to the 'Energy Boost' node or something.
I imagine it's on your to-do list but adding hot-keys would be great as well, space bar to buy a selected node is a no brainer imo. Navigating through the Nodes with hot-keys might be a bit of a challenge to setup though.
But great work, could easily see this being a popular game with youtubers :D I'm keen to see how far you take this game <3