>>12113476
Flat perspective. Stage art in X1 and X3 tends to have an overhead-like perspective to it, with X4-X6 going fully into that like Ristar or Kirby Super Star. X2, instead, has most stage graphics be done with a flat perspective, sort of like the NES Mega Man games. To be fair, it might have been for visual clarity, so it's not necessarily a bad aspect, either.