Hi! Thanks a lot for your detailed feedback!
I unfortunately wasn't able to implement the actual objective in time but to boil it down, you'd keep upgrading and while exploring find generated structures, some requiring special equipment to open, which would let you escape.
The mining progress thing is intended but I might consider reworking that a bit or at least telegraphing it better to the player.
And as for the clicking, i didn't quite consider how exhausting it'd get but I've already implemented the ability to hold down the mouse button to automatically mine (the downside being that it might not be as fast as clicking), which will release in a small patch after the voting period.
After that's done I'll have to do some major technical cleanup but I'm looking forward to implementing everything I originally had in mind!