* MarthDebutedInSmashBros: Dr. Arewo Stein from the [[NoExportForYou Japan-exclusive]] GameBoy game ''VideoGame/ForTheFrogTheBellTolls'' makes several appearances in ''Wario Land 4''.
** In a more literal sense, the music for the first level of "Shake It!" makes a couple of appearances in SuperSmashBros Brawl: as Wario's victory fanfare, and as part of the [[MarioKart Waluigi Pinball]] track
* NamesTheSame: ''Wario Land: Shake It!'' has a level called [[VideoGame/PaperMario Mt. Lava Lava]].