World-In-A-Bottle Map

I've seen a few "World in a bottle" type maps on here, and since I think it's such a cool idea, I decided to make my own take on it as a break between some of the larger, more complex maps that I've been making.

There are no specific "challenges" with this one. It's totally free play (and I would love to see what you create in the void!) but feel free to limit yourself with rules like