The walls are very high – you can’t escape unless on creative mode, or by teleporting.
I recommend adventure mode as the stone walls can still be broken on creative and survival.
There are no rules as such – you can make your own!
All game settings work on this world so it’s up to you what you do with it, you can set your own spawn points, add chests, mob spawners, etc.
Here is the official trailer:
Here are some in-game screenshots:
