A soloing of the game is an in-universe Crowning Moment of Awesome done over and over again. Whatever hero you are from Daredevil to the Incredible Hulk to Magneto, you are faced with the entire rogues gallery of nearly every villain on Earth-616. By the end of it, you've managed to defeat everyone from Doctor Doom to the Mandarin to the Red Skull and more. Not bad for a cosmic hero, let alone street one.
Parker Robbins manages to get one despite being a Villain Protagonist. He manages to steal the Tablet of Time from the heroes right after they defeated Doctor Octopus, only to sell it to Madame Hydra before they manage to capture him. Except, when Madame Hydra tried to pull a Ballistic Discount, he ended up double-crossing HER and setting Hydra against the Hand with Elektra on his side. For a wannabe crime boss, he pretty much made everyone look stupid.
Sharon Carter/Agent 13 gets one of these as she manages to avoid being a Damsel in Distress and rescues herself before you get a chance to do so.
Doctor Doom gets a "The Reason You Suck" Speech from Dormmamu as well as the Watcher about how he's playing with forces he can't possibly comprehend. In the end, he pulls a Did You Just Punch Out Cthulhu? with both of them. Given Dormammu rules multiple dimensions and is a being who Physical Gods pray to, this is an achievement even Stephen Strange would envy.
