Making a SUPERMAN game is EASY!
The main problem people bring up as an obstacle to making it work is that Superman is "invincible".
As any reader of his comics will tell you: HE'S NOT! He gets beaten up a LOT!
THE PROBLEM is that people keep projecting him into the Batman and Spider-Man games, seeing it does not work. Of course it doesn't work, because the enemies there are dudes with guns and other regular weapons! Those things don't work on Superman!
SUPERMAN SHOULD FIGHT SCI-FI AND FANTASY ENEMIES, BECAUSE THEY ARE THE ONES THAT ACTUALLY THREATEN HIM PHYSICALLY!!!!!! (Monsters, Aliens, Robots, Clones, Wizards, etc! Just use his Rogues Gallery as an example!).
Another problem is: What if the player plays the game like a mass murderer, and not as "good person"?
That's where Infamous Second Son's Karma System comes in: Reward the player for performing good actions and punish him for performing bad ones! EASY!
See how easy it is?