1. Solid for the first 8 hours, the last couple levels and ending are a bit of a letdown in comparison to the overall game quality up until this point.
2. 12 hours
3. Not really
4. 92
5. Yes, but it's very very short as I recall.
My advice would be to wait until after Christmas, given the extremely poor first 2 days sales in Europe and how it will probably be clobbered this week it should be a very inexpensive pickup once retailers start heavily discounting it.