TrackMania

Personally I'm fine with the concept of having stuff locked behind some training in a game, but I also think it's a bit too strict as is - I think there should be room to skip a map. Maybe instead of eg. requiring 20 gold medals, reduce it to 18 gold medals or something. In other words: I like the mechanic, but I also hope they'll adjust it a bit in the future.

I didn't really have issues with getting the medals, but for a newcomer it might be a bit too much of a wall. But then again, it's not as clear cut as "newcomers who can't instantly complete them will quit". Obviously some people will quit, but for some other players the unlocking mechanic can work as a clear goal to aim for, and works as a reason to become better at the game - without the unlocking mechanic (as it used to be), the content in the game can feel a bit "aimless" for a newcomer, and the lack of a clear goal can also make people quit.

As with everything in games, it's a balancing act. I guess (hope) they're just testing it for now, and check some statistics to see what works.