Hey!
I can see how the ending might feel like a bit of a departure from the main game. My intention was to give a sense of urgency and of a desperate push to escape, but NOT to actually make the ending difficult, frustrating, or overly time-constrained. But I might have missed the mark a bit. Thanks for the feedback here!
As for the "Stellar Cache", I'm a bit confused unfortunately. In my test run, I only needed to build a single one of those. Did you perhaps mean the "Star Ash Capture Mesh", so the buildings that produce "Stellar Remnant"? I can see how that might be a bit frustrating, so I've reduced the resource requirements here.
I've updated the game (v1.1.0) which softens the curve of the resource requests towards the end and removes the timer from the ending sequence, to keep it a bit more in line with the rest of the game.