- There are two sides to every battle, good and evil. Or Good or Evil. Both can be used to motivate hatred and pride. But it doesn't make it the truth. Only one man refused to succumb to that. However, he is caught between Light and Darkness. Which can be unbalanced, but unique. He is unique. At first I thought of him as a failure. I was wrong, he is unnatural. He is the more than unique, he is a god among man and mutantkind itself. He is my Son.
- --Apocalypse describing Matt
X-Men: Son of Apocalypse is an open world game set in the X-Men universe. The protagonist is a half mutant drifter and ex-special forces operative named Matthew "Matt" Crowe, the youngest son to the mutant En Sabah Nur also known as Apocalypse. The game later spawned a sequel, X-Men: Kaiser
Running from his ashamed father Apocalypse, Matt Crowe suffered an accident that generated his powers. After being discharged from the Chicago Police Department, Matt soon found himself in New York, where he was to fight not only the human authorities (such as the MRD and the US Military), but also the X-Men and the Brotherhood of Mutants.
The gameplay is a cross between Prototype, Incredible Hulk: Ultimate Destruction, Spawn: Armageddon, Saint's Row and Devil May Cry.
- Matthew "Matt" Crowe
The titular protagonist of the game, Matthew Crowe is a 25 year old Kaiser (Half mutant) and a former US Army Delta Force operative. Born of his mutant father En Sabah Nur (Apocalypse) and his human mother Janet Crowe, Matt didn't receive his powers until he was exposed to an accident that trigger them. However, unlike most mutants he learned how to control his abilities all by himself without any trouble. Matt is a cynical and dry young man, firmly holding little regard for anyone, except his mother. Matt is an atheist and believes there is no such thing as Good or Evil, firmly believing that both Xavier and Magneto are fighting a war he considers to be based on perspective and opinion.
- Janet Crowe
Matt's mother and navigator. She often supports her son through two way communication. When Matt got his powers, she originally suggested to him to go the Xavier Institute. But due to Matt's animosity with the war, he refused.
- En Sabah Nur/Apocalypse
Matt's father. When Matt was born, Apocalypse was ashamed to realize that Matt had no powers and felt the need to kill him. Ever since that day, Matt and his mother were hunted by him ever since.
- William Rolfson/Holocaust
Matt's half brother and the favored son of Apocalypse. When Apocalypse discovered Matt's powers he started to favor him over William. This lead Holocaust to hate his brother and was determined to kill him. He is the main antagonist of the game.
- Anna Marie/Rogue
Rogue appears as both a major character and as a boss in the game. She understands Matt and was disgusted with his scoundrel like attitude considering him to be Gambit clone minus the womanizing and laid-back outlook. Despite that she also wishes to come with him in order to get out of the war and convince him to teach her how to control her powers. Her appearance is a cross between her appearance in X-Men: Evolution and Wolverine and the X-Men.
- Charles Xavier/Professor X
Charles tries to understand how could Matt control all his powers. Charles asks him to the join the X-Men. When Matt refused, Charles remained patient. But due to Matt's slight lack of regard for humanity, he will send the X-Men to stop him from committing any more damage to New York. Despite this, Xavier admires Matt's reasons for not entering the war and wishes to stand in his place.
- Max Eisenhardt/Magneto
Magneto is impressed with Matt's abilities and persuades him to join the Brotherhood of Mutants. When Matt refused, Magneto would not stop until Matt joins the Brotherhood.
- Rémy LeBeau/Gambit
Despite Gambit's affiliation with the X-Men, he assists Matt from time to time when it comes to fighting either the Brotherhood of Mutants or the MRD.
- James Howlett/Logan/Wolverine
Logan dislike Matt for being such a "punk". Matt feels the same way as he does.
- Jean Grey
Appears as a major character and a boss in the game. She feels sympathetic towards Matt.
- Dominikos Petrakis/Avalanche
A member of the Brotherhood of Mutants. His powers involve geological manipulation via seismic wave generation.
- Warren Worthington/Angel
A member of the X-Men and a boss in the game.
- Bobby Drake/Iceman
A young X-Man with the power to generate and control ice.
- Scott Summers/Cyclops
Cyclops is the field leader of the X-Men and Charles's heir.
- Kurt Wagner/Nightcrawler
Kurt understands Matt's reasons for not joining the X-Men. Despite being an X-Men, Matt respects Kurt and his pacifism to the point of becoming friends.
- Katherine "Kitty" Pryde/Shadowcat
A young X-Man and a boss in the game.
- Hank McCoy/Beast
Appears as a boss character and the X-Men's medic in the game.
- Raven Darkhölme/Mystique
Magneto's second in command.
- Pietro Maximoff/Quicksilver
Magneto's estranged son. Pietro wishes to regain his father's trust in him.
- Victor Creed/Sabretooth
Wolverine's former partner and rival.
- Frederick J. Dukes/Blob
A fat, but incredibly strong mutant. He is rudely called a "fatso" or a "fat motherf*cker" by Matt.
- Jubilation Lee/Jubilee
A young mutant and a daughter figure to Wolverine.
- Ororo Munroe/Storm
A close friend of Charles Xavier and a veteran member of the X-Men.
- Mortimer Toynbee/Toad
A young and thuggish member of the Brotherhood of mutants. He is the easiest boss to defeat in the game.
- John Allerdyce/Pyro
A member of the brotherhood and a controller of fire.
- Wanda Maximoff/Scarlet Witch
Magneto's daughter. Despite being close to her brother Quicksilver, Magneto favors her over his son. She is referred by Matt as "Scarlet B*tch".
- Commander Stephen Lang
The commander of the Mutant Response Division.
- Senator Edward Kelly
Senator Kelly is an anti-mutant extremist and an antagonist in the game.