In Mario & Luigi: Bowser's Inside Story, the characters are deathly allergic to wearing inappropriate clothing. If Mario and Luigi are made to wear Bowser's clothes or vice versa, all their stats drop to 0. It is unknown if this is merely a code quirk or an intentional failsafe.

In Super Mario Sunshine, there is a small plant in Gelato Beach that raises a staircase when sprayed with water. In the files, an unused, presumably corrupt animation for it exists that shows it slowly stretching in an unsettling manner.