A Boy and His Blob: Trouble on Blobolonia is a side-scrolling platformer in which the character and his friend Blob (full name Blobert) travel together on Earth and on Blobert's home planet Blobolonia in a quest to defeat an evil emperor. Blobert can change into several different items when he is fed jelly beans. A licorice jelly bean, for instance, will change Blobert into a ladder, while a honey jelly bean will turn him into a hummingbird. Most of these transformations can be remembered mnemonically due to a correlation between the flavor of the jelly bean and the item that results. Whistling at Blobert causes him to change back, often with a musical accompaniment similar to the main theme.