Godzilla Unleashed: Double Smash

The Nintendo DS version of Unleashed, Double Smash features gameplay akin to a side-scroller, similar to that of the Godzilla: Monster of Monsters. Although graphically 3D, its 2D gameplay made it similar to titles such as New Super Mario Bros. or Sonic Rush. Using the two-screen display of the Nintendo DS, flying monsters appear on the top screen, while grounded monsters appear on the bottom screen. A multi-player option allows for a different player to control each monster. Critical reaction to Double Smash was largely negative. IGN gave the game a score of 3 out of 10, saying: "None of the recent Godzilla games have been very good, but at least they were fun. Godzilla Unleashed: Double Smash cannot make this claim. It looks terrible, and reduces the King of the Monsters to a mush of no-texture polygons, then puts him in a tedious series of punching planes and kicking boats." GameSpot gave Double Smash a 2 out of 10, calling it "one of the worst DS games ever made," adding: "With a perfect storm of terrible game design, bad play mechanics, and uninspired destruction, this game does what oxidation bombs, volcanoes, and Matthew Broderick couldn't: It kills Godzilla." GameSpy gave the game a 1 out of 5, saying: "This brain-dead combat is perhaps the worst part of Double Smash. Slowly plodding through the stale levels, fighting the same enemies, and using the same techniques to win grows old almost immediately."

The storyline of Unleashed, taking place twenty years after Godzilla: Save the Earth, begins with a meteor shower raining down on Earth, causing climate shifts and earthquakes. Simultaneously, the monsters of Earth begin to attack cities across the globe as a result of crystals growing on the ground. Factions form among the members of Earth as well as the monsters attacking them, totaling four monster factions. Choices within the story affect later events, including the relationships between Earth factions and the monster ones. The Vortaak, returning from the previous games, choose to invade and use the crystals to seize Earth, but their mothership is knocked into San Francisco bay. It is revealed in the finale that the source of the crystals is from SpaceGodzilla trying to escape the alternate dimension he was imprisoned in at the end of Save the Earth. There are four (five as alternate) endings based on the factions; if one wins as an alien, Vorticia cackles maniacally in victory. If one wins as a mutant, the crystals spread at a cancerous rate, proliferating out of control. If SpaceGodzilla wins, the Mutant ending commences, except that SpaceGodzilla is subsequently seen letting out a victory roar. If the GDF or Earth Defenders win, the player's monster is thanked for their bravery as the world returns to normal. If the Earth Defenders, GDF, or Alien acquires all the power surges, Miku said that the monster became corrupted and it was the only hope. Contrary to popular belief, It doesn't have alternate endings yet in which an Alien or Mutant turns face and saves the Earth(essentially false rumors).