I saw this movie yesterday, expecting cheap laughs and simple humor.
I was so surprised that it was just laugh after laugh after unceasing laugh.
The reason it's so funny is because it's a mockery of all action movies. There are puns and ridiculous scenes that could only work in a spoof. And then you have Ryan Phillipe who is normally a serious actor, adding to the deadpan humor. :)
Most scenes are great. It has been a long while that I can say that over 85% of the movie is hilarious. There were no lulls. Just constant laughter.
Go see it. It will make you die laughing, which is a great thing.