Zelda: PH takes place in the same world as Wind Waker (for GC) with the same characters (Link and Tetra). The boat is different, though.
The game starts with Tetra being kidnapped by the crew of the ghost ship, and Link waking up on a beach (similar to other zelda games). A fairy whose name escapes me currently, finds him and tells him to come meet her grandfather, who is also the leader of the village. Link does so, and determines he wants to save Tetra... and the adventure begins.
This is a pretty basic zelda game... and very similar to wind waker. Except that it's completely controlled using the stylus... which... makes the game absolute balls. moving, attacking and drawing are all controlled using the stylus. It's a terrible system and it wore me down really quickly, making it impossible to play this game for any significant amount of time.
The ship control is also very limited and slow... making travelling on the world map quite a hassle. You draw where you want to go on the sea chart, and the ship takes you there. You control the camera... and you can jump over sea traps. Not overly appealing.
I would type more but I am getting carpal tunnel from this shitty game so... you can read/view more about the game
hereedit: I just got the boomerang... it's pretty cool. You draw a line from yourself to where you want it to go and it will follow it exactly unless something is in the way.