In order to do so, 'hatching crystals' must be obtained through various mini-games found around the island. On the subject of the eggs, just gathering them up isn't enough to hatch them i.e.
Just the same, if you leave the area without solving the riddle on the first or second try, it may result in the egg not being thereupon returning to said location. Reentering the area afterward will not guarantee the egg still being there. If the question is answered incorrectly thrice, the T-Rex will show up to attack and you'll be forced to retreat to the next area. Terrence will let them know where an egg is hidden but in order to properly reveal it, the player must correctly answer a question in the form of a riddle and click on the animal/plant/etc that corresponds to the area. The eggs can be found throughout all three regions and will often pop up out of nowhere while the player is exploring. To help Rolf in his fight, the player must help him locate nine dinosaur eggs that were scattered across the island during one of the T-Rex's attacks and hatch them in an inactive volcano dubbed 'Hatching Ground'.
Guiding the player is a young wise-cracking parasaurolophus named Rolf, along with his friend Terrence (a humble yet friendly Pteranodon), who has a plan to dethrone the resident tyrant of Paleo Island, namely the ferocious Tyrannosaurus Rex a.k.a. Dinosaur Adventure 3-D takes the player on a journey through Paleo Island, an environment that has prehistoric animals, including dinosaurs obviously, from all three stages of the Mesozoic era (Triassic, Jurassic, and Cretaceous).