My take on it:
Yes, I know, the title should have warned me off, but I couldn't resist watching it!
Daniel Craig (the current James Bond, for the benefit of any readers from other planets) plays a gunman in the Wild West who wakes up with no memory but with a hi-tech bracelet firmly clipped around his wrist. At the same time, people are being attacked and captured by small flying machines. One of these crashes, and the tracks leaving it indicate that something decidedly non-human was on board.
A motley posse sets off on the hunt for the alien, and then in search of the source of these flying machines with the hope of rescuing the captured people. Apart from Craig, this includes Harrison Ford as a rich farmer, Olivia Wilde as eye candy (though she does turn out to have a role to play) and various assorted lawmen, cowboys, criminals and even Indians.
This is a lightweight and forgettable film but makes for a couple of hours of trivial entertainment, preferably watched in well-oiled social company in the mood for a laugh.
I do have one gripe (at the risk of a mild spoiler): why are "bad" aliens in such films always shown to be hideously ugly monsters with such deliberately evil intent? Do the film makers not realise that evil wearing an innocent face is far more chilling? Or that the activities of aliens on this planet might incidentally have a disastrous effect on humanity even without any evil intent? Or is such subtlety beyond their comprehension (or at least, more subversive than they think their target viewing public will accept)? Oh well, I suppose I'm expecting too much of a lowest-common-denominator popcorn movie based on (and closely resembling) a comic strip. To be fair, though, the good guys do not all get to live happily ever after.
(An extract from my SFF blog)