

A bunch i really liked were:
- Hades (and Hades 2) (action roguelike)
- Dead Cells (side scroller roguelike)
- Celeste (Precision Platformer)
- HexCells (puzzle game)
- Shadow Tactics: Blade of the Shogun (Stealth Strategy, the other games by the same dev are great too)
- Prey (well, maybe its not an indie, but its great)
- Vampire Survivors (Bullet Heaven, great to zone out too, lots of things to collect)
- BugSnax (Not sure if Indie, but a lot more fun than it looks)
- Cave Story (Side Scroller)
- Creeper World 4 (Strategy game, I think 4 is the most recent. No need to play older ones unless you want more of the same)
- Earth Defence force 6 (janky, but fun multiplayer with friends)
- Heros Hour (strategy)
- Oxygen Not Included (colony builder)
- Rim World (colony builder)
- Satisfactory (Automation game)
- Pit People (strategy game)
- Supraland (puzzle game, sequel is fun too)
- The Talos Principle (Puzzle game, I think its indie?)
- Undertale (RPG, its fantastic)
- You must build a boat (Match 3)

Dwarf Fortress is linux compatible, although I haven’t played it in years its a colony builder that can get super in-depth. Its interface is a learning hurdle though.
You might like Conan Exiles, its a sandboxy survival game that just got updated recently with better graphics. I kind of feel its more a exploration game than a builder though. Hrm…