Go through the first part
of the level, and when you come to the area with the UFOs,
inhale one and take it's ability. Head back through the
door you just came in and go below the Swordsmen and head
below to the left.
You'll be under the whole
first area of the level, where a well hidden door will be
guarded by blocks. Charge your UFO power up and break the
blocks to enter the door and grab the last switch for
Orange Ocean.
