What disturbed me even before seeing it was that it wasn't 3D. I know I said the same thing about Batman, but in this day and age anything that is sci-fi or action should be in 3D in my opinion. It is what saves cinemas. It was first colour, then widescreen, surround sound, now 3D.
The basics of the story stayed true to the original. It's still about a guy who doesn't know which memory is real or not. There was a hooker with three breasts. However, don't expect him to go to Mars, because he doesn't. The movie is still exciting, still full of action. It is mostly action, very little actual story. That lacked to me.
The change of planet was a bit odd. I won't be giving too much away when I reveal that it's on Earth because part of that is polluted due to a chemical war. Just a part of Europe and Australia is habitable. Therein lay a few technical problems. For example, we can see that the area around Big Ben is fine, but Piccadilly is covered in a dense yellow fog. Now how come that stays there, and doesn't float over? There is also a lift that goes through the Earth's molten core. I can't imagine anything being so strong as to stand such heat. I think they would have been better sticking to the Earth - Mars thing.
The purpose of sci-fi is not just to satisfy us geeks. Future sci-fi is about showing what comes from the world we live in today. Will we resolve our problems, or make things worse? Here it's obviously worse, but unlike in a dystopia, things get better. Still, let's not have a chemical war, okay?
Collin Farrel did a good job replacing Arnold. He fought, muscles flexed, and he looked good even bloody and dirty, something an action hero must do. He was also sufficiently confused.
Jessica Biel is good at being the female action hero. She can make bloody and dirty hot. I always find it funny that she tends to do these roles when she started out as little Miss Christian in Seventh Heaven. If she intended to erase her clean-cut beginnings, I'm sure she had been successful.
I hope I won't ruin anyone's surprise if I reveal that Kate Beckinsale is a villain, and plays it well. She runs after our heroes, and pulls off the determined and slightly manic look in the eyes well.
Overall, it's a fun action movie. If you saw the original, you won't get many surprises in the story, though the action is different.