This game contains a roster 30+ characters. 21 are playable from the start, 9 are unlockable within the game, and 9 are DLC. Here, you can see the characters and learn a bit about them, and where they originate.
Sonic The Hedgehog
Faster than the speed of sound, Sonic has his title as SEGA's flagship character. With a love for adventure and chili dogs, he spends much of his time defending the world from the evil Doctor Robotnik. Origin: Sonic The Hedgehog (1991)
Knuckles The Echidna
Knuckles is Sonic's rival and guardian of the Master Emerald on Angel Island. With the spikes on his fists, he can smash through anyone and anything that tries to take him on. Origin: Sonic The HedgeHog 3 (1993)
Alex Kidd
Alex Kidd is an orphan who inhabits the planet Aries. With a mastery of the Shellcore technique, he can increase the size and toughness of his fists, in which he has smashed his way through many adventures. Origin: Alex Kidd in Miracle World (1986)
NiGHTS
NiGHTS is what is known as a "Nightmaren" who lives in a world where human dreams come to life. Despite his childish personality, NiGHTs has proven to be a versatile justice fighter with the ability to transform and flight. Origin: NiGHTS Into Dreams (1996)
Ulala
Ulala is a reporter for the future news station, Space Channel 5. With a great sense of rhythm, she can not only report cases well, but she can also blast her ways through many alien threats. Origin: Space Channel 5 (1999)
Joe Musashi
Joe Musashi is a shinobi raised in New York. Armed with his sword, Hazy Moon, along with ninjutsu skills and spells, he cut his way through the criminal organization, Zeed, and many other opponents. Origin: Shinobi (1987)
Ax Battler
Ax Battler is a barbarian who teams up with Tyris Flare and Gilius Thunderhead to fight the evil Death Adder to avenge his mother wh was slain by his forces. Armed with his great sword skills and seismic magic, he is a great fighter capable of dealing with multiple opponents. Origin: Golden Axe (1989)
Akira Yuki
Akira Yuki is a Baji Quan martial artist who enters the Virtua Fighter tournament in order to hone his skills. Surrounded by these new adversaries, he has been given this chance to demonstrate these skills even further. Origin: Virtua Fighter (1993)
Jack Cayman
Jack Cayman is a chaser who originally earned his spotlight as a contender of the deadly combat sport, Deathwatch. Underneath his hulking frame and dual-chainsaw arm skills is a caring father who hopes to avenge his daughter's death. Origin: Madworld (2009)
Bayonetta
A member of the endangered Umbra Witches, Bayonetta fights against the angels of heaven to achieve the goals she seeks. With her pistol skills and strange magic, she's one of the most unpredictable fighters in this game. Origin: Bayonetta (2009)
Ryo Hazuki
Ryo Hazuki is a teenager who travels to China in order to get revenge on the man who killed his father. While he seems like a normal teenager, he is able to defend himself from many odds with his mixed martial arts skills. Origin: Shenmue (1999)
Dr. Robotnik
Dr. Ivo Robotnik, or as he is continously called "Eggman", is a mad science bent on conquering the world. He may not seem like much, but with his brains, robot army, and modification he made to his capsule, he's an opponent that Sonic suely enjoys besting. Origin: Sonic The Hedgehog (1991)
Death Adder
Death Adder is a tyrannical seprpentine who stole the legendary Golden Axe, and with its power, he has tried on many occasions to conquer the world. A persistant villain, he is definitely a very powerful opponent that the other will attempt to surpass. Origin: Golden Axe (1989)
Tyris Flare
Tyris Flare is an amazon who teams up with Ax Battler to defeat Death Adder in order to avenge her amazonian sisterhood that were slain by his forces. She's more speedy than Ax Battler and has great fire magic skills and beast mastery, proving to be as capable as her partner. Origin: Golden Axe (1989)
Kara
Kara is a valkyrie a who decides to take up battle after being inspired by watching the warriors on Earth in their great battles. A spunky fighter armed with a spear and the thunder of gods, she can viewed as a fun opponent for the others. Origin: Tournament of Legends (2010)
Blaze Fielding
Blaze Fielding is a former police officer who fights alongside Axel Stone and Adam Hunter to stop a crime syndicate from plaguing their hometown. A judo fighter who has many odds in the past, she is welcome in this battlefield. Origin: Streets of Rage (1991)
Sarah Bryant
Sarah Bryant is the sister of Akira Yuki's friend, Jacky, who was originally brainwashed to fight against him, and now fights alongside her brother in the tournament to take down the syndicate that brainwashed her. Taking up mixed martial arts, she's proven to be a decent fighter. Origin: Virtua Fighter (1993)
Welkin Gunther
Welkin Gunther is a young commander of Squad 7, who joined after his hometown was involved in the Second European War, and gained command after helping another town evacuate. He is well armed scout and strategist, who may even be able to fight through these opponents, even with Squad 7 on his side. Origin: Valkyria Chronicles (2008)
Sam Gideon
A researcher of DARPA, Sam Gideon created a special Augmented Reaction suit, and with it, he teams up with Team Bravo to fight against the Order Of the Russian Star. While a bit reckless, the prototype suit and gun skills makes him into a capable opponent. Origin: Vanquish (2010)
Sakura Shinguji
Sakura Shinguji is a young samurai who fights alongside Ichiro Ogami, captian of the Imperial Assault. Despite her appearance, she's a skilled swordswoman who is not to be underestimated. Origin: Sakura Wars (1996)
Aliasse
Aliasse is a pure-blooded Valkyria who joins Avan Landins of Class G after being used to experiment with her powers. She mainly uses her powers and weapons to protect her friends, but here, she doesn't intend on holding back. Origin: Valkyria Chronicles 2 (2010)
Unlockable Characters
Shadow The Hedgehog
Shadow The Hedgehog was created by the late Gerald Robotnik to be the ultimate lifeform. After the original sacrificed himself, Eggman created a clone, who would eventually become a rival of Sonic's. With great speed and the power of Chaos Control, he has earned the title. Origin: Sonic Adventure 2 (2001)
Metal Sonic
Metal Sonic is a robotic version of Sonic created by Dr. Robotnik to defeat him, only to be defeated and eventually become obsedded with proving his superiority. He is equal to Sonic in terms of speed and skill. Origin: Sonic The Hedgehog CD (1993)
Kage-Maru
Kage-Maru is a ninja of the Hagekure clan who enters the Virtua Fighter Tournament to avenge his father and to seek out his kidnapped mother. He uses his clan's style of Jujutsu, making him unique as a ninja fighter. Origin: Virtua Fighter (1993)
Marcus Antonius
Marcus Antonius is a selfish gladiator who fights to maintain a title and have everyone remember his name. While he often resorts to trickery, his strength alone makes him a formidable fighter. Origin: Tournament of Legends (2010)
Alis Landale
Alis Landale is a young woman who saves the Algo solar system while following a request from her brother to foil the plans of the evil King Lassic. Armed with sword and an arsenal of spells, she has earned her skills as a hero. Origin: Phantasy Star (1987)
Michael Ford
Michael Ford is a member of the secret service who gets between a conspiracy between an organization called "The Trust" and an invasion from an alien race, The Drudge. With a gun mastery and an artifact known as the All-Seeing Eye, he will show how he gained his job and why he would eventually be called the destroyer. Origin: The Conduit (2009)
Vector the Crocodile
Vector the Crocodile is a leader of a group of detectives called "Chaotix Detective Agency". Large and imposing, he can fight through many things to solve many crimes... as long as it pays. Origin: Knuckles' Chaotix (1995)
Big Bull
A former competitor of Deathwatch, Big Bull is the mechanical leader of a gang that is active in the city of Altambra. While big and strong, he tends to leave himself wide open and isn't exactly brains. Origin: Madworld (2009)
Hibana
Hibana is an Oboro kunoichi who was enlisted by the Japanese government to find the demon sword, Akujiki. Like Joe Musashi, she has plenty of speed and ninjutsu skills to take over a battle. Origin: Nightshade (2003)
DLC Characters
Amy Rose
Amy Rose is a hedgehog who is obsessed with marrying Sonic, and as result, she gets herself involved in many of his adventures. While she isn't much in speed, her Piko Piko Hammer packs quite a punch. Origin: Sonic the Hedgehog CD (1993)
Silver the Hedgehog
Silver the Hedgehog comes from a post-apocalyptic future to attempt to fix it, only realize this can't be done and stays in the present as a rival of Sonic's. While slow, his telekinetic abilities give him much range even when cornered. Origin: Sonic the Hedgehog (2006)
Espio the Chameleon
Espio is a ninja who is a member of the "Chaotix Detective Agency". His combat skills are pretty speedy and his ability to turn invisible makes him a tricky fighter. Origin: Knuckles' Chaotix (1995)
Vyse
Vyse is a rogue who is a member of his father's crew who is able unite his own crew into a great fighting force. He wields two powerful cutlasses, though his magic skills are a bit pale. Origin: Skies of Arcadia (2000)
Selvaria Bles
Selvaria Bles is a Valkyria and Brigadier General who holds resentments after being experimented on, and she fights alongside the Drei Stern. She contains a lot of power in her Valkyrian form, but even alone, she is a skilled soldier in combat. Origin: Valkyria Chronicles (2008)
Dan Marshall
Daniel Marshall is a member of the special forces who alongside his group, Rust Crew, take on the Amada Corporation and their army of humanoid robots. Dan is well-equipped and is the heaviest of the military fighters. Origin: Binary Domain (2012)
Hotsuma
Hotsuma is a headmaster of the Oboro clan who goes out to defeat the demons that appeared in Japan by the demon sword, Akujiki. He's almost as fast-paced as Joe in terms of combat skill and wields projectiles. Origin: Shinobi (2002)
Candy
Candy is an aspiring apparel designer who enters the Viper Tournament just to show off her work. Despite her odd motivations, her Aikido style shows that she's no pushover. Origin: Fighting Vipers (1995)
Rin Rin
Another former competitor of Deathwatch, Rin Rin is a member of clan of assassins called the Crimson Dragon, alongside her two sisters. She has good martial skills, and her fiery-blade fans are efficient weapons. Origin: Madworld (2009)