Pokemon Advanced Generation Planetarium: Tenkuu Kara no Chousen
Genres: Action, Adventure, Comedy, Fantasy
Type: Movie, Episodes: 1
Aired: Jul 17, 2004
Source: Game
Rating: PG - Children
Synopsis:
This is a world where people and Pokemon live together in peace.  Satoshi from Masara Town set out on a journey to train to become a Pokemon Master.  One day, Satoshi and Pikachu visit a forest with lots and lots of Pokemon.  Suddenly, Satoshi and Pikachu are swallowed up by a world of darkness!  The "Galactic Dark Lord" appears from the depths of this darkness and starts taking the Pokemon from the forest!  Satoshi and Pikachu decide to stand up and fight in order to help rescue the Pokemon.  Please enjoy this show, which features a huge Pokemon world filled with stars, all the way up until the end!

(Source: Dogasu's Backpack)