Adventure Mode is the single player story mode of War of the Monsters. The Player chooses a monster then plays through each level with that monster. Completing adventure mode rewards the player with the Origin Story of the monster they used, aside from Raptros and Zorgulon.
There are 11 levels total in War of the Monsters: Adventure Mode. Each level completed rewards the player with battle tokens which they can unlock different skins for each Monster. The Raptros and Zorgulon are not available by default and must be unlocked after accumulating enough tokens and buying them. From there, further skins can be purchased and they can also be used for Free-For-All mode.
- The player must defeat Togera and then Robo-47 while surviving the many tanks, missile trucks, and attack helicopters in Gambler's Gulch.
- The Player must defeat several Mutant Ants, then immediately after must defeat a robotic Boss Monster Goliath-Prime in Rosdale Canyon.
- The Player must defeat a reanimated Mecha Congar and Preytor in Metro City with some attack helicopters patrolling the four central skyscrapers.
- The Player must battle and defeat several Kineticlopses while destroying the
energycooling towers generating them, in Atomic Island. The player then fights another Boss Monster, an enormous plant-like monster called Vegon.
- The Player must battle Magmo and Agamo in Club Caldera. Several flying saucers also serve as enemies, if only minor nuisances.
- The Player fights two Ultra Vs in the city of Tsunopolis, with some attack helicopters patrolling the city, mainly around the two tallest skyscrapers in the center. After defeating it, they are abducted by aliens.
- After being abducted to Alien mothership, the player must fight three Zorgulon and multiple turrets and UFOs.