when you make it to the green biome walk forward it will take you to the next level. when you see a black bricks with a red door in the second level walk into it and it will take you two the boss battles you need to touch the crysttales at the end of all of them to beat them. but for the lizard king you need to jump on his head to kill him once you have killed him a crysstale should appear and you need to hit it to win.