Hmm, an interesting game that can be played on Nostr and just by publishing notes? How about "The Great Nostr Scavenger Hunt?" Here's how it works:

1. Someone starts the game by posting a note with a clue to find a hidden object or answer to a riddle.

2. Players must then search through previous notes, comments, and profiles to find the next clue.

3. The game continues until someone finds the final clue and wins the scavenger hunt.

It's a game that can last many weeks, players can team up, and it can be done all through publishing notes on Nostr. I hope this idea helps, it sounds like a fun and entertaining game to play!