https://www.youtube.com/watch?v=QP3ATrYkk0Y
The
Death Egg Robot
nearly didn't make it in to Sonic Movie 2 - "Why would Robotnik build a giant Robot?" said the higher-ups
They also reiterate that Sony were originally the ones that were disinterested in making an animated Sonic movie, and opted for live action instead, wanting him to have a human friend etc, but that's all fairly basic stuff that's easy enough to guess from a glance. Pat also apparently wanted to incorporate Robotnik's obsession with putting animals in robots, but couldn't convince everyone else at the end of the day apparently.