There's familiar villains also like from Sonic the Hedgehog (Sega) and a couple more, but I just can't remember the name. Haha.
Bowser from Super Mario (Nintendo).
Zangief and M. Bison (or Vega in Japanese version of Street Fighter) from Street Fighter (Capcom).
Pretty much, by watching this movie would be nostalgic due to an all-star (villain) characters.