Source: Wikipedia, "[en.wikipedia.org/wiki/Kao_the_Kangaroo Kao the Kangaroo]", available under the CC-BY-SA License.
Kao is a young kangaroo living with his family in the jungle when they are one day captured by a ruthless hunter and his goons. It's up to Kao to drive the invaders from his home and save his family.
The game is divided into 5 sections "worlds" each with a distinctive theme (winter, space, tropic etc.) however, the sequence of levels often makes little to no sense, for example, a battle with some kind of Greek god (Zeus, probably) transitions into a level in outer space.