First two acts great, the third OK, and the very end a disaster

Rating: 7/10 (15 January 2008)

It was definitely different than I expected. I AM LEGEND is the story about Colonel Robert Neville living in a post-apocalyptic NYC that has been cleared of humanity everywhere, all over the globe. He spends his days hunting food and gathering supplies with his only family, his beloved dog Sam. He tries making contact with any survivors at noon. At night, though, he locks himself up and listens as the vampires overrun the city.
However, the movie is not about the vampires. The movie is really about Robert Neville, a man desperately hoping for contact with the outside world. Its about his character, the way he copes with everyday, and his strong-willed mission to find a cure for the vampires. But things aren't so easy for Neville; accidents happen, and Robert Neville does encounter them on several occasions, and these encounters are rather intense.
A common criticism of the movie is the look of the vampires. I'll admit, they aren't scary and don't have the best special effects, but the main focus with them is suspense and surprise, which is done really good. Although the surprise is a little overdone; the movie is filled with pop-up moments, which to me, is not real suspense. I don't mind an occasional pop-up, but there are many in this film. However, these are my only complaints for the first and second act, and these are minor. My main problem is the third act.
The third act is where it really strays from the book (I never read the book but already know the ending). The third act includes a lot more humor (which is funny, but a bit out of place), less humanization, and a showdown that isn't very climatic. It culminates in disappointment, and suddenly ends. The entire resolution is done in a 30-second voice over, and this movie deserved a much better ending. It feels like its not supposed to be over yet, and my friend and I both agreed that it was like we were just watching the movie and someone pulled the plug and says "Ok, the movie is over. Bye." It was extremely disappointing. I didn't even know it was going to end until the voice over came.
This movie could've been great had the third act stuck to the book (I like the book's ending better), and the ending wouldn't have disappointed. Will Smith does a great job of adding elements of sadness where it is needed and really fleshes out the character, Robert Neville. I even have to say the dog was great; it seemed human because it was really the only other character, and I like their interpretation of Sam rather than the books. But that doesn't excuse the decaying third act. 7.4/10