Mario Box Deluxe
A gigantic Mario-themed skybox!
Good for residence, parties, playing around on, or just showing off, this sucker is an enormous piece of 8-bit architecture so retro it should come with background music. Seriously, just look at this thing.
In all seriousness, though, this skybox represents at least five different environments from the original Super Mario Bros. NES game (or six if you count the mushroom platforms by themselves). The blocks are for decorative purposes only and thus will not explode or yield untold pixelated riches on impact, but the pipes actually do work! In so far as you can jump or fly into them, anyway. The various platforms are all reachable via jumping, though this does not necessarily mean the jumps won't be tricky.
The skybox is also all one colossal object, and as such does not require one of those weird building-part-placement blocks. Just shove the thing wherever you've got room for it.
As an added bonus, if you find you actually can't fit it anywhere, a smaller econo-Mario-box has been included, containing just the basic overworld and underground areas, tucking into a 22.5 x 22.5 meter space instead of the 22.5 x 44.25 meters the full-sized behemoth requires, and sliding in at 47 primitives instead of 242.
Enjoy!