Here is the full list of all 32 Gigantosaurus The Game achievements.
Complete the Adventure
Collect all pages in the Gigantopedia
Collect all Walnuts
Collect all statues
Plant seeds in all seed pots
Stop all streams of lava in the Volcano
Collect all Golden Skulls
Break all snowmen in the Glacier
Finish 1st in race from the Glacier to the Volcano
Find 10 eggs in the Glacier
Find 4 eggs in the Glacier
Finish 1st in race from the Lake to the Glacier
Shoot all coconuts on the island in the Lake
Sail 200m in a canoe in the Lake
Find 10 eggs in the Lake
Find 4 eggs in the Lake
Use the secret cave slides in the Jungle
Shoot 10 baskets
Finish 1st in race from the Desert to the Lake
Find Trey at the Oasis in the Desert
Find 10 eggs in the Desert
Find 4 eggs in the Desert
Stun 10 critters
Finish 1st in race from the Jungle to the Desert
Find 10 eggs in the Jungle
Find 4 eggs in the Jungle
Use all fun objects
Finish 1st in race from the Savanna to the Jungle
Stun all carnivorous plants in the Savanna
Visit the 5 chambers in the secret cave in the Savanna
Find 10 eggs in the Savanna
Find 4 eggs in the Savanna