I was first introduced to this movie after my sister insisted I watch it for years and years and I finally sat down to watch it and now I want to strangle her. An absolute mess of a film that could've been SOOOO good. You would've thought that putting Neil Gaiman (who has wrote several great works), Dave McKean (an accomplished artist) and the Jim Henson Company together would make for a great movie but this falls so so short.
If I remember correctly, they wanted to do another fantasy film comparable to Labyrinth and The Dark Crystal so the decided to shit this one out, albeit with a much smaller budget and it definitely shows. Terrible CGI, random nonsense plot, bad acting with awkward dialogue, scenes that make you think, "what was the point of all that?".
This movie actually has rabid fan base that is absolutely crazy about this movie and there may be a few here. I think they're so distracted by the imagery and I guess the whole "world" of MirrorMask to the point where they fail to realize it's actually a pretty crappy movie. I'm sure there are a ton of 5-star reviews from users even though it bombed commercially and was panned by critics... and anybody else with good taste in movies.
http://www.youtube.com/watch?v=GA1iawlsKLg