Okay! We were discussing this, so sorry for the delay. It's not so much the length of time that a character spends in a game, but how those experiences affected them and their relationship with other people, their own universe, other universes, etc. We have one character already in game who spent only a month in her game, but due to the nature of it, it changed her profoundly. Other characters in-game have not had their personalities changed significantly, but their world views and understanding of reality.

Apologies if that's a little nebulous. But our general criteria isn't based on length of time in a game. It's more 'Has this character been substantially affected by their CRAU experiences to make them notably distinct from the straight from canon character? That can mean different things for different characters.

Just from the sound of it, Sonic would likely have enough CRAU experience to qualify, but we'd have to see an app. We'd urge you to simply highlight his cross-canon interactions and the new things he learned from his time in his other game!