Stone Protectors

A kingdom powered by crystals is under attack by the Saurians. Their leader, called Zok, wants the kingdom's powerful crystals to himself. Breaking into the castle, Zok reaches to take the crystal but it explodes into pieces. All but one of the crystals reaches New York and falls into the hands of a rock band, who are transformed into goblins by the power of the crystals. Now their goal is to bring back the pieces to the kingdom and fight Zok and take his piece. (mobygames.com)