My top rec would be Factorio if you like sandbox building games (almost RTS, but not quite). Talos Principle 2 is the best puzzle game I've played (might not be indie, but I don't think it's a large studio). Last Epoch is a solid ARPG like Diablo, but more old-school in how it plays and feels. Outer Wilds is also an amazing exploration, narrative-driven game.
Talos Principle 2 was a masterpiece. The concepts explored in the story were really interesting to boot, I also did not anticipate it to be so stunning visually.
