Now I understand

What you tried to say to me

And how you suffered for your sanity

And how you tried to set them free

They would not listen, they did not know how

Perhaps they’ll listen now

For they could not love you

But still your love was true

And when no hope was left in sight

On that starry, starry night

You took your life, as lovers often do

But I could have told you, Vincent

This world was never meant for one

As beautiful as you

• Vincent by Don McLean

A few more recommendations in the same vein: Fibrillation HD, Antichamber, Manifold Garden

I second Kingdom Come: Deliverance. Seems like it ticks all of OP’s boxes.

You and me both. NMS happened to show up at a time in my life when I really needed peace and quiet, so the slow pace and solitude of the gameplay was great.