We're In - we being me and @keith-courage.

Premise: A small version of the world is contained Within The World Itself (and mounted on a turtle).

Self explanatory?

Initial Sketch

This means whenever the turtle gets jostled, the whole universe shakes! It'll be a 2D platformer with the turtle acting pretty much like a Mario turtle. But since it is also the containing universe if it bounces off a wall everything gets jerked to the side.. and so forth. Of course the World-Turtle may be immune from those physics effects since that would likely create an infinite loop. It's a special turtle. Let's see how it goes!

(The premise is from the Futurama episode The Farnsworth Parabox and from the Turtles All The Way Down story)

Using: - Unity 5 - Sketch