If your game allows people to hold stuff: A small purple Stegosaurus that the player can pick up. It ever so slightly grows in size whenever you enter a new room. Once it is big enough you can use its tail as a ramp to get to a new area, otherwise inaccessible.
Thank you, can't wait for you to try it and I hope it lives up to those. I love The Stanley Parable and I'm trying to do my own thing in that tone, (the final part of the game really gets unhinged)