I went with a few mates(including a few who were a bit dubious about its potential),none left not entertained. It might not be the latest Merchant Ivory production in terms of character development but it had frikkin large mecha on screen beating the crap out of assorted monsters so I didn't care,and neither did anyone else it seems. The first time proper mecha have popped up in a Hollywood film and it was shiny. I like shiny.
Eat your heart out Transformers.
Plus it has epic theme music:
http://www.youtube.com/watch?v=1DABGdvCOs4
Courtesy of the bloke who does the GoT music.