Saad

Super Mario Bros. Wonder uses 2D animation techniques with 3D models by manually deforming each limb on every frame of an animation. Above are three successive frames of Mario's "pipe exit" animation; note the lengths of each of his legs.

Most previous Mario games have worked with regular 3D animation techniques where Mario's limbs were always a constant length and bending deformed them in a predictable way without stretching them. More recent entries in the series, like Super Mario Odyssey, experimented with squashing and stretching, but not on a frame-by-frame basis like Super Mario Bros. Wonder.