Tim Burton's The Nightmare Before Christmas: The Pumpkin King GBA FAQs, walkthroughs, and guides

Once a holiday king, Oogie Boogie has so ruined his August holiday of
celebrating bugs to the point where his holiday has completely ceased to exist.
Therefore, he has decided that if he can’t have his own holiday, then Halloween
will do nicely. Meanwhile, Jack and the citizens of Halloween town notice that
unusual bugs have started to infest their township. Unable to figure out where
these creepy crawlers have come from, Jack and his trusted pal Zero embark on a
journey to locate the source of the ever-increasing bug invasion. With help from
familiar faces, such as Sally-the-Mayor, and the inventions of Dr. Finklestein,
Jack discovers that the bugs are under the command of Oogie Boogie. Now, it’s up
to Jack to rid the town of this new infestation, and stop Oogie Boogie from
carrying out his evil plot. This is the story of how Jack Skellington met Oogie
Boogie, and how he saved Halloween.