Just one warp? Did it say that in the help at the beginning? There does not appear to be a way to view that again once the game starts.
There's no in-game affordance to indicate hitting Tab will open the upgrade menu.
There's no indication in the upgrade menu what each upgrade will do or which value (idle or click) will increase.
The cost and value of the x2/x4 upgrades increases at the same time. So it becomes a fixed number of clicks to get to the next one.
It doesn't idle when it's not the active element. So we can't leave this game running and earning while we do something else on the computer.
Everything is behind the planet. So if we're clicking and an asteroid flies up and gets hit, we have no idea how much it was worth. Though probably not much. It does not appear to scale with the other sources of income.
Not game specific, but why is the area given by Itch.io so large, when the game only takes up a small fraction of it in the middle?