A Super Mario Bros. X Thing: Prelude to the Stupid was the first major game developed by the Talkhaus through the Super Mario Bros. X engine, and is the second game in the A Super Mario Thing series. It follows Demo and Iris collecting leeks through "The Castle of No Significance". In addition to Demo and Iris, three other characters are playable; Kood (from Drama Mistery), Raocow, and Sheath (from ATXS).