There's not much plot and the acting is absolutely weak in some areas considering that this movie is loaded with some great actors. Daniel Craig, Harrison Ford, Olivia Wilde, Sam Rockwell, Clancy Brown, Keith Carradine, and Paul Dano all star in this movie. Even more annoying is Craig's struggle to maintain an accent. Remember Kevin Costner in Robin Hood? I do.
On another note, the effects are quite possibly some of the best I've seen in the theater this year. The aliens are all CGI but maintain a sense of realism and a certain depth that was lacking in films like Green Lantern.
Overall, I would suggest seeing this movie just for some fun entertainment. But don't run out and see it. There are many better things to watch right now..........like Captain America!