From the back of the box:
It's an Evolution Revolution!
If you were a monkey, just hangin' out in the jungle with your chimp-chick, and a magic ruby fell out of the sky and zapped you both, turning you into half-humans, and a demon-kid swooped down and made off with your girl - what would you do? You'd high-tail it after them and stop at nothing to save her, that's what - 'cause you're Congo, the monkey-turned-superkid, and only you can uphold the Law of the Jungle! But it's more than a jungle out there - your search for little Congette will take you from ghost towns to pirate ships to ninja castles to the belly of a Tyrannosaurus. This is no time for a banana-break - you'd better get down to monkey business!