Project gorgon as others have said is the first native game that comes to mind. Guild wars 2 runs great on proton and that's my recommendation. FF14 is great if you don't mind the subscription and can get through the vanilla campaign, which is a massive slog and a major setback in the quality of the game IMO. Guild wars 2 is a similar situation in that it's a slog for the personal story, but after that it picks up and that's only like 40% of the vanilla campaign as opposed to the whole vanilla campaign of FF14. The FF14 fanboys don't want to talk about the vanilla campaign and for good reason, it sucks, it's just not fun. The game doesn't get good until heavensward.