*Important note: this isn't really a movie, more like a TV special episode*
This side-story takes place in the series somewhere before the demon tournament. It's a rare focus on Yuusuke's boss, Koenma.
Animation: Same quality as standard TV episodes, meaning it's not that hot. Still, it's good compared to other series I've seen.
Sound: Same as above.
Story: It's really amusing having George the Oni in charge of Yuusuke & Co. but it isn't that great of a story, since they had to wrap it up in a standard episode length. If it were longer, they could have done so much more with it.
Characters: Main point of this special was to flesh out the characters of Koenma and George. The rest of the characters still hold thier own personalities well.
Value: As a whole, this could be skipped. It's a completely optional side-story, though the amusement factor has some draw. It has no bearing on anything else in the series.
Enjoyment: It's quite a hoot figuring out who the bad guy is in this special. This is one of the times that YYH uses liberal comedy to entertain the audience, and they pull it off well without being too silly.