Communicating sanity through audio rather than a UI meter is a nice touch, though I'll echo other comments on not effectively knowing when I'm about to cross the sanity fail-threshold. This made it a little frustrating when the flashlight is such a scarce resource. That got pretty manageable after a few retries. I do appreciate the sigh letting me know I can turn off the flashlight.
I had to restart a couple times from getting stuck on the geometry, though I understand that a lot of it is godot doing godot things. Reducing the friction in the physics material on the character body might help!
*Spoiler Warning*
Radio at the end was hard to discern, made me wonder whether there was an actual person or my character had fully lost their sanity, it's nice for making the narrative tie into the sanity-management system.