Complete effects guide for Stitch (Version 0.00).
Enter the green door. Go north-west and interact with the jack-o'-lantern among the pumpkin patch.
Enter the purple door to the Sinking City. Go down and you should see a metal bridge forming a path across the water. Walk onto the bridge then go down the narrower path of the bridge to the other side. Interact with the roller skates beside the bench.