He throws boulders at Po, and then he escapes when the player reaches him. Master Shifu is then briefly assigned to stop the gorilla army from destroying the temple and find the Kung Fu Relics.
Later, Po finds Great Gorilla and his henchmen and fights them. Eventually, after a fight between Po and Great Gorilla, he's defeated by Po; he falls to the ground and his eyes roll into the back of his head.
The Great Gorilla was shown to be rude and arrogant, showing that he really didn't have any respect for Kung Fu (as mentioned by Master Shifu in the game), unlike Po.
Great Gorilla appears to have no Kung Fu skills, as he does little but throw boulders and use his heavy fists in battle.
Great Gorilla wears sparse armor, relying on his thick skin for defense.