Mighty No. 9 is a side-scrolling arcade action platformer that is the spiritual successor to the Mega Man series. At the beginning of the 21st century, there was a breakthrough in the robot industry, and everyone started making machines controlled by artificial intelligence. A special coliseum was created for the robots, where they fought like gladiators. Nine powerful creatures stood out in particular — until something went wrong and they were infected with a virus. You have to try on the role of the ninth robot from this team, who for some reason did not become infected, and get to the bottom of the truth.