It's an ok movie, just saw it.
The effects are good as said, and the story was given to us in moderation and what was relevant. (I'm sure most movies just have a long scene where everything is explained)
I didn't like how Ash suddenly appeared with the light around him... does that make him the king of the sea or crowned by the sea crown or something?
My last annoyance (my personal one) I'm too cheap to buy the dvd version so I usually tape the pokemon movies when they appear on tv. So first of all my vcr won't tape so I'm halway into the movie before I realize this. I figured I could just tape the second showing of it at 9:00, but the second the first movie finishes the second one begins! I was able to tape, but luckily I got it in before it went to the Manaphy egg.
Now here is something for you all to chew on...
Since the anime usually shows all legendary pokemon, they're going to show Phione some day. But... if May is gone when Manaphy comes back (because Manaphy would be its parent!) with Phione what is going to happen? A sequal perhaps?