You know I thought I was going to be unique with this one.
This game gave me so much fucking anxiety that I couldn't finish it. The dark atmosphere and the constant whispering in your ear made me feel like I was straight up hallucinating. It fucked with my head so hard.
To add to this, I would highly recommend not worrying about using a .10mm layer height until you have reliable prints at .20mm height.
Trying to get finer detail is just compounding issues onto a print that looks to have quite a few things wrong.
I agree with you on underextruding. Easiest way to test would be for OP to measure 150mm of filament from the entrance of the extruder and mark it. Set nozzle temp to 215 or so, and manually extrude 100mm. Then re-measure to your mark and see how far off you are. If it's way off OP needs to calibrate his extruder motor steps.
Also as other people have said, might be worth trying a different filament, especially if that filament is really old.
I honestly could not make it through the first... 4 or 5 episodes. Didn't help that I had just reread the series prior to watching and it honestly felt like they went out of their way to completely shit all over the source material.