Scaler follows the story of a 12-year-old boy named Bobby Jenkins who stumbles across the evil plot of his next door neighbor to dominate the world through use of mutated lizards. His neighbor, Bootcamp, captures and restrains Bobby, striking him with a bolt of energy that transforms him into a shape-shifting alter-ego, Scaler—a vivid blue and yellow mutant lizard with razor sharp claws, a long tongue, and the ability to shift into several other kinds of lizards.
Unbeknown to Scaler, Bootcamps leader, Looger controls a network of unstable portals that are the only connections between the different dimensions in the multiverse. Any being in control of these portals would have the ability to move freely between the different worlds, and even capture them. Looger has managed to accomplish this through the use of a device created by a scientist named Leon, who was consequently exiled through a portal to a desolate world. With the portal being his only escape route, Bobby "Scaler" Jenkins escapes from Looger through the portal and must now travel the strange world he arrives upon in his new form in order to find and defeat Looger or all of the universes will go into darkness.
The main attraction of Scaler is the ability to transform into five different types of mutant lizards, each one giving some sort of advantage depending on the environment. As the character journeys to different areas of the world, he will occasionally be given a challenge to defeat a number of special foes, thus giving the ability to transform into them and use their unique abilities to his advantage. Each area he journeys to allows him to transform into only one of this five forms.
After its release in 2004, Scaler received mostly positive reviews. While receiving praise for its high production values and gameplay, some reviewers criticized it for having an unexciting plot and formulaic design. It currently bears a composite critic score of 70 out of 100 on Metacritic.