Yes, you can actually buy this thing.

From Etsy user CatastrophiCreations:

Our Super Mario complex comes complete with portals that are lined with sisal, so (cats) they can climb in and out of their blocks. The blocks are all attached and have a tunnel that allows the kitties to climb in one portal and out the other. What about the prize box, you ask? Well, this box is made out of pet resistant screen that allows you to see inside of it. Throw your kitty’s favorite toy in and watch him play! You get your own prize in watching him flop around inside his box.

[CatastrophiCreations on Etsy.com | Via Kotaku]