Rarest is terrible. I absolutely know that baked ube is a street food, and way less likely to be guessed than Udon, and yet I'm penalized for nobody else guessing it yet?

I didn't even play latest and oldest, because that's just a guessing game.

Oldest is fine and fun. It's oldest in terms of when, not answers. The oldest pyramid for example.

I agree that the rarest wasn't nearly as entertaining or fun. Perhaps that one needs a list to pick from.