From the back of the box:
TEAM UP WITH THE DINOSAURS FOR A SUPER-HUGE ADVENTURE!
Uh oh, you've just been launched into the prehistoric age by a whacko TV monitor, and the biggest thing going is dinosaurs! Luckily, the dinosaurs have a huge liking for time travellers like you and your friend. Now you just have to solve the problem of the Neanderthals. These cave heads are out to destroy "DinoCity" - and all the dinosaurs in it. So hop on the back of your favorite dinosaur, and get ready for some fast-action fun on a very LARGE scale.