Are there any good indie games on the world's largest video game store? I dunno, are there any leafy trees in the Amazon?
From what I've been playing: Stardew Valley, Factorio, Vampire Survivors, Derail Valley, A Hat In Time, Project Wingman, Frostpunk 1 and 2, Portal 2 (technically self-published), Signalis. Voices Of The Void will eventually have a Steam release. All of those games work well on Linux.