Looking for PC hidden gems with online co-op (steam spring sale preferred)

Looking for new games to play online with 1 or 2 friends. We have pretty broad tastes. RPGs, Roguelike/lites and Suvival/Crafting are our most played genres. Have played most the big titles in these genres looking for deeper cuts that might be on the current Steam sale but definitely willing to step out of the comfort zone for quality games (especially if there a good discount right now).