Tenebrarium: sit back, place a few resources, and watch the Teno work it out

Tenebrarium is an idle-like alien colony simulator: you place resources, then watch the Teno — a volatile species that can fuse with their surroundings or explode into a pile of bones — grow a colony as you learn their behaviours. It has a hand-crafted retro pixel-art look, a lo-fi sci-fi soundtrack, and a lot of weird little guys, plus post-game sandbox modes after the story wraps. Windows only.

You don't steer the Teno directly, which is the charm and the catch. It isn't a fully hands-off idle, because the colony can starve if left alone, and the Teno-pilot and ingot endgame can feel obtuse.

It's still early days, so take this as a tentative recommendation for anyone who likes watching small simulated creatures and teasing out cause and effect.