Spiritfarer.

The soundtrack, art direction, color palette, and gameplay all come together in a relaxing loop. I have spent hours just drifting along spot to spot, taking care of the spirits in my care until their times came to depart, and still go back to it when I just want to have some time to relax.

As a warning, the game does deal with some emotional tones, so there's a bit of melancholy mixed in. My wife and I both had times where we teared up because it felt like saying goodbye to someone again. It's handled well, though. Really gives the feeling of everything being put to rest, and there's still everything they taught you right there as a reminder of the effect they had.