Swim through the water while avoiding Gordos, fish, and frogs. In a room where enemies can be copied off from, try copying off a flame wheel for the fire ability. Cross over spikes with Gordos and use the door on top. Defeat a swordsman to free Coo then use the next door to see enemies over crumbling floors with spikes. In the final room, you’ll battle Blocky. Defeat it and the goal will appear.