Mutant Mudds developer Jools Watsham has revealed that Mutant Mudds Deluxe sold more on Wii U than Steam, PlayStation 3 and PlayStation Vita combined. However, Watsham says that Mutant Mudds has sold the most on the Nintendo 3DS.
Interesting tidbit. Mutant Mudds Deluxe has sold more on Wii U than the combined sales on Steam and PSV/PS3.
3DS is king. :)