Both characters retained their familiar movements, which creates an amusing effect.
It is especially noticeable how complex the task is for Sonic Team. Sonic's worlds are enormous, yet they do not feel cumbersome during gameplay. Sonic handles the Super Mario 64 levels with ease, while Mario in Sonic Adventure looks noticeably slower and more compact.
The video clearly illustrates the difference in the design of the worlds and the characters' movement, and also shows just how large Sonic's locations are.