Teen Titans - Master of games character list

Apprentice Hero: An alternate version of Robin,
Beast Boy Hero: Teen Titan capable of shape-shifting into animals,
Blackfire Villain: Starfire's sister; plays exactly like Starfire,
Blocker Henchman: Robotic fighting machine,
Bumble Bee Hero: Uses powerful twin lasers,
Bunnyguard Henchman: Mumbo Jumbo's bodyguard,
Cinderblock Villain: Made of concrete and stone, strongest character in the game,
Clown Beast Boy Hero: An alternate version of Beast Boy,
Control Freak Villain: Attacks with a variety of sci-fi gadgets,
Cyborg Hero: Part-robot with enormous strength,
Cyclone Hero: An alternate version of Cyborg,
Dr. Light Villain: Uses the power of light to attack,
Fang Villain: Plays the same as Gizmo in his mecha-spider,
Gizmo Villain: Attacks with mechanical contraptions of his own design,
Hive Soldier Henchman: Works for the Hive Academy, a school for supervillains,
Hotspot Hero: Uses powers of flame to attack,
Jinx Villain: Jinx's powers of bad luck are translated into powerful energy attacks,
Mad Mod Villain: Wears an exoskeleton designed after the London Royal Guard,
Mammoth Villain: Uses his great strength to defeat his enemies,
Mega Meaty Meat Beast Boy Henchman: An alternate version of Beast Boy,
Mumbo Jumbo Villain: A diabolical magician,
Plasmus Villain: Blob monster army leader encountered during story mode,
Plasmus Kid Henchman: A fighting blob monster,
Raven Hero: Fights with ranged telekinesis attacks,
Red Raven Hero: An alternate version of Raven,
Red X Villain: Robin's alter-ego come to life,
Robin Hero: Acrobatic melee fighter,
Slade Villain: Arch-enemy to the Teen titans, clever fighter,
Slade Minion Henchman: Generic foot soldier in the employ of Slade,
Speedy Hero: Attacks with bow and arrow,
Starfire Hero: Powerful ranged beam attacks,
Tempest Henchman: Robotic fighting machine,
Terra Hero: Geomancy powers let her attack with rock projectiles and landslides,
Trigon Villain: Raven's demon father fights with flame attacks and powerful punches,
White Raven Hero: An alternate version of Raven,
Wildebeest Hero: Powerful man-beast.

Multiplayer Mode Characters:
All you have to do is just play through Story Mode and eventually unlock characters.

Multiplayer Mode Characters - Play through Story Mode

Multiplayer Mode Stages
Just play through Story Mode to unlock Multiplayer Mode Stages.

Multiplayer Mode Stages - Play through Story Mode

Unlockable Arenas:
City Cathedral - Complete City Night Showdown Level
Larry's World - Complete Danger Yard Level
Mad Mansion - Complete 1st part of Jail of Horror Level
Mumbo's Big Top - Complete 2nd part of Magic Mayhem Level
The Hive - Complete Hive Academy Level
Raven's Mirror - Complete Thriller Driller Level
Sky Needle - Complete Titan Tower Level
Titan Tower - Complete Slade Ambush Level
Slade's Lair - Complete Final Clash Level

Concept Art:
Each Larry the Titan you find in a level, unlocks concept art in the gallery extras menu.