Moon Child offers a pretty wild combination of themes and genres, it's almost like watching 10 films at the same time. It's definitely an ambitious project, sadly it's not all that consistent. Zeze does it best to keep everything together, but not everything works as well as it should and the constant jumps in quality become tiring after a while.
Performances are pretty poor, but that's not too surprising considering there's quite a few pop idols (like Gackt) taking up the lead roles. Some better actors in secondary parts, but their roles aren't big enough to make a difference. The bits of drama and romance aren't too successful either, getting in the way of the fantasy and action and putting a break on the pacing.
On the other hand, the action scene are pretty slick and there's some visual trickery that is quite entertaining. The setting too is pretty intriguing, with some novel multicultural and fantasy elements that set it apart from other films. Zeze may not have been in full control of his film, at least it's a pretty cool train wreck.