The total number of playable monsters differs between the Wii and PS2 versions. The former has 26 playable monsters while the latter has 20. In both versions, monsters are divided into 4 factions: Earth Defenders, Global Defense Force, Aliens, and Mutants. In Story Mode, monsters of particular factions have different goals and take on a different order of missions. Each faction also has different styles of play and what they consider friend or foe. Some choose to destroy the crystals to get rid of them while others intend to abuse their powers, and so will reflect this depending on how the player chooses to act throughout. As players gain points with some factions for obtaining Power Surges, obtaining all seven Power Surges will null any allegiances the player has and unlock a secret level called "Tyrant", in which the player's chosen monster is given unlimited Critical Mass, but is forced to brawl against several monsters who may or may not have been former allies. In addition to the established Toho created monsters, two original creations were developed for the game. The lava-based Obsidius was selected from a roster of 4 original monsters created by Pipeworks while the aptly named Krystalak was included by default in the Wii version.
Earth Defenders Natural monsters who are very instinctive and protective of their territory,
Earth. They see the crystals and Vortaak as threats and will go out of their way to destroy them, even if it means destruction of human cities. The Earth Defenders will ally themselves with monsters that destroy crystals while attacking those who use them to attain Critical Mass. •
Anguirus (Showa),
Baragon (Showa/Millennium hybrid),
Fire Rodan,
Godzilla 1954 (Wii only; cannot be used in training or story mode),
Godzilla 1990s (Available in PS2 and can be used in story mode; cannot be used in training or story mode on the Wii version),
Godzilla 2000,
King Caesar (Showa/Millennium hybrid, Wii only),
Mothra (Heisei/Millennium hybrid),
Varan (Wii only)
Global Defense Force Human engineered
mechas built to protect humanity from other monsters, the Vortaak, and the crystals. The GDF will ally themselves with monsters who fight the Aliens' monsters and the mutants, and minimize destruction of human structures. Due to their autonomous minds, GDF mechas can fall victim to and become corrupted by the crystals' energy. •
Jet Jaguar,
Kiryu,
Mechagodzilla 2,
Mecha-King Ghidorah,
M.O.G.U.E.R.A (Heisei)
Aliens The Alien faction is made up of monsters that have allied themselves with the Vortaak invaders and thus want to destroy the humans and conquer Earth. Alien monsters are driven by power surges and attack monsters that destroy Surge crystals, Vortaak forces, and alien buildings. They also ally themselves with those who preserve crystals and destroy human forces. •
Gigan,
King Ghidorah,
Mechagodzilla (Wii only),
Megalon, Orga
Mutants Monsters from the mutant faction are driven by a lust for power. They are drawn to the crystals and will destroy all in their path to get such power. Mutants will ally themselves with other monsters who fight everyone else and are willing to attain Critical Mass. They will also attack monsters who do not cause enough destruction. •
Battra (PS2 Only),
Biollante (Wii only),
Destoroyah,
Krystalak (Wii only),
Megaguirus,
Obsidius,
SpaceGodzilla,
Titanosaurus (Wii only)
Unplayable •
Atragon During production, several monsters were scrapped. The originally designed monsters who lost in the polls were known as Fire Lion, The Visitor, and Lightning Bug.
Hedorah was considered, but was scrapped because cel-shading him proved to be time-consuming.
King Kong was scrapped due to legal problems with
Universal Studios.
Zilla was considered, but scrapped due to his overall negative reception, though fans later criticized this decision. Monster X was considered, but scrapped due to his transformation sequence into Keizer Ghidorah being too complicated and the game engine could not handle more than one person playing as him at a time.
Gamera was mentioned in an interview, and likely not included since he is owned by
Kadokawa. ==Development==