The motor sitting towards the top left corner looks like it has a robotic face on it. Also, the end of the stage has that classic Sega skyline!!!! Beautiful.
Blaze, Adam and Axel used calling the back up cop (either using a bazooka or Gatling/machine gun) as a special attack against the enemies in the first Streets Of Rage game. Estel Aguirre is the successor of the calling the back up cop (bazooka only) as a special attack this time against the heroes (Axel, Blaze, Adam Hunter, Adam's daughter Cherry Hunter and Floyd) in Streets Of Rage 4.