The mod is a total conversion/mini-game mod for Skyrim and adds new enemies, items, mechanical interactions, and an entirely new "kingdom." The mod introduces the player to a separated mini-game within Skyrim, but the worlds are individual and will otherwise not interact; that means you can install this mod and play in the Mario world without impacting your Skyrim settings. Continue on for the video.
In the feeling of Super Mario 64, the mod introduces multiple worlds to Skyrim, each of which has a different theme. You can view a preview of the mod here: