Let's trade feedback! I submitted a project too. Congrats on finishing a simple game loop on your first Jam.
Gameplay: It starts out fairly slow but does ramp up after getting enough buffer miner. The minions didn't seem to have as much impact as I'd expect, if you invest a lot into it. The Buffer miner is much more apparent in the ramp-up. Perhaps have the minions increase in size or different types are summoned if you continue to invest in that.
UI Interface: I recommend adjusting your Godot settings to the game can go full-screen. Or on your ItchIo setting page enable the full-screen option there. Hard to play with the UI so small.
PowerUps / Buyables: I get starting out with one buyable, the minions. But after getting that 5 times, I think two powerups should unlock instead of just Buff Miner. For every 5 investments, two more Powerups should unlock. So that I feel I actually have to weigh my choices in where I invest. Right now, the choice is linear for such a long while. A better system is unlocking two powerups at a time for player sense of urgency in using their limited energy.
Art: Good use of the many asset packs you listed. Very simple concept as a clicker game. The level doesn't change; fairly straightforward. It'd be cool if the level change over time based on the energy you gathered. Or if there are NPC's that pop up trying to escape the planet. Or rockets appear in the background showing people escaping. Or perhaps the sky darkens the longer you wait. Adding cues over time to show how critical this situation is and the effect on the world we're in / trying to save.