I'm glad to see other people think we need more openly themed games.
I have enjoyed a lot of games with restricted themes, recently Metroid prime 2 mafia and Fire emblem mafia 2, but those are because I know the games well enough and there are enough characters that false claims are pretty viable. Playing a restricted-theme game without knowing the theme is extremely difficult, I remember playing Morrowind Mafia and not knowing a single thing.
If you do want to make a restricted-theme game especially on a very niche series, make sure that the game is not focused explicitly on the flavor of the game and that there are options for people who haven't played the game before.
I think the best restricted-theme game to look at would be Fire Emblem Mafia here.
If you know anything about Fire Emblem, then you'll know that it's not based on any 1 specific game, the conflict is not flavor based at all, and there are a number of completely unrelated characters to aid in false claiming.