Ori and the blind forest is a great platformer that is about 8-10 hours long.

Donut County is a fun little game that takes about 5 hours or less.

Axiom Verge (and 2) is a neat Metroid like game that is around 15 hrs.

Factorio. Once you get a hand of it you can work in small chunks here and there, or pour in hours and hours of time.

Check out neon exdeath. Not exactly synthwave but close.

Nothing yet. They did a post saying they don’t have anything to share as of 12-30-2022 FFF-372

Not sure if you’ve tried any mods but I would of you haven’t yet.