I'm super-late to the party (and my first-ever jam), but I'm planning on making my entry focus on Musical Instruments (I actually have an idea for a suite of musical-themed L&F games), as they pass on from musician to musician! It opens up a whole can of worms for time-frames and settings, but I also think it would allow a playthrough to go from the Renaissance all the way up to modern-day, and beyond (ideas/tips/tricks/thoughts welcome)

just found out about this jam and am already so excited about it and all ideas in here are sounding awesome!

I'm thinking of a game about city buildings and architectural styles, so doing playbooks like The Brutalist, The NeoClassical, The ArtNouveau, The Post-Modern etc and the agents being like possible uses/functions (city hall, hospital, school, church, department store, prison, big-shady-internet-company warehouse)

Someone mentioned a recipe; what about a song, legend, prophecy, or breed of plant or animal? 

Would the evolution of a new breed of sheep count, so you'd follow each successive lamb rather than an immortal sheep?

If a song changes over time, then someone digs up the original, which version does the song see as the "true" version?

When a prophecy comes true, does it die? When humans think it has come true, does it feel the same way?

I had an idea before but I have my actual idea now: Every Room A Mouth.

EVERY ROOM A MOUTH invites the player to step into the shoes of a house—watchful, rotten, and full of hate—that will never be a home, as it seethes and growls and feeds on mortal flesh and tragedy. You’ll feel the centuries bear down upon you as horror festers in your heart, walls crumbling and roof sagging as you wait for your next victim.

It’s all about haunted houses, baybee!