Mayhem is an unhappy dinosaur, as Monsterland is an unhappy place, due to an apprentice magic dinosaur who decided to practice some of his master's spells, after drinking too much cactus juice. Mayhem decides to change it back, with the help of Theo Saurus, the apprentice responsible for Monsterland being the gloomy place it is now.

The game is a side-scrolling platform game, where you play the part of Mayhem. You can kill enemies by jumping on them.

There are five levels in the game. Each one starts in unhappy mode, where Mayhem must collect enough bags of magic dust, from the enemies you face, then find your way to Theo's hidden cave. Theo then uses the dust to make the level happy again. This change is reflected in the more jazzy music, colourful landscape and even the monsters who look more friendly and cheerful.