Why "Folklore" might be my favorite theme suggestion ever.

This made it to the final round last year for LD50 and I was pretty disappointed that it lost. I wound up getting sick and having to abandon that jam anyway, but I'm hoping it comes back and wins someday.
There's a huge amount of source material for inspiration, and with no restrictions on game mechanics, it allows for a lot of variety. I had more immediate game ideas that ever before, here's what I came up with in about 5 minutes:
A pet simulator where you need to take care of a Griffin or Cerberus.
A Pac-Man style game where you play as the Wendigo from American Indian folklore, chasing down people to eat them.
A stealth game where you need to avoid a Minotaur as you escape the Labyrinth.
An idea I had for "Mirror" was a game where you're hunting Medusa, but you can't look directly at her, only her reflection around corners.
A racing game like Mario Kart on Rainbow Road, where you're chasing a Leprechaun to the end of the rainbow to steal his pot of gold.
A Pokémon Snap style game where you're trying to snap pictures of Bigfoot or the Loch Ness Monster.
A quiz game featuring the Sphinx.
A sea battle simulator where you need to fight off a Kraken.
A simulator where you're a Mermaid having to do Seaworld-style tricks.
The Monkey King of Chinese folklore could have mechanics based of either the cloud he rides on, or his shrinking/extending staff.
A hunting simulator where you need to track and kill a Jackalope.
A sumo game where you play as Paul Bunyan competing against Goliath.
...and some more that came to mind afterwards:
You're a werewolf who keeps transforming back and forth whenever the clouds cover the moon. Attack as a wolf, hide as a man.
A snowboarding game where you play as a Yeti
Game Genie. Basically just make any game you want, but every time the player starts, they can choose three cheats to have enabled.
Stealth game where you're an alcoholic and have to steal a beer from the Devil's Chair in Florida without paranomal investigators seeing you
"Untitled Chupacabra Game"
A rhythm/music game where the Fremont Troll of Seattle comes to life and starts a grunge band
A Q-Bert style game where Jiangshi are hopping after you
Have you seen the dogs playing Poker painting? Werewolves playing Poker.