There was a PnC adventure game I have vague memories of, it was a kid-friendly game and had reasonably open design... I can't remember its name to save my life, but I wish I could because I really loved it.
I'd also say that even though it's not exactly hidden, the original Starship: Tribes was one of the best shooters I've ever played. I hate that it was largely forgotten and ignored. I mean, Ascend was a solid game but ruined by microtransactions. That series deserved so much better.
I feel like console add-ons would have been better for everyone. I like the idea of being able to squeeze more life out of an existing console because it means not everyone has to rush to get the new one. Modular upgrading is one of the bigger reasons I'm a PC gamer.