Top-down (or 3D side-view) “Indiana Jones” or “Jumanji” like temple puzzles. (Secret traps, stones you can and cannot stand on, locked doors, hidden caves, etc.)
Make it an adventure game like the first Zelda (GMTK video inspired) => many different screens or rooms, all interconnected. By unlocking one thing, you can go somewhere else. And there are cryptic riddles everywhere.
Of course, the game can be played as local multiplayer! (Is that a different mode from single player? How?)
But what’s the extra twist?
- When you download/buy/install the game, it generates a random seed. (From current time, from player name, from computer ID, whatever.)
- This seed is used for ALL the random generation in the game.
- Every puzzle has the same overall “structure” (for example, find the hidden path or uncover the secret code), but the details and the actual solution are randomly generated.