A game where you play as a generic NPC or enemy without the power to leave your screen: you're trapped in a loop, waiting for the player to arrive. However, in this world your powers come from what you carry, and you can steal what others carry... When the player arrives, you can steal the power to move between screens. Once you have this power you become, to some degree, "the player," where you were not before.
Something like that.
Had this idea a very very long time ago. I'm not sure what it's all about, but it's still appealing to me.