Andy Serkis's performance as the ape Ceasar is at times quite frankly breathtaking. Sometimes just the subtly of the emotions he would convey without words would bring me to the brink of tears; heck, half of the time I forgot he wasn't even saying anything but I felt it all. I wouldn't even be surprised if this might be the role that brings his controversial hybrid acting method to the level of Oscar-nom.
As for the rest of the film, the acting was mediocre at best, but part of me thinks that the filmmakers were more concerned with nailing the apes than nailing the human acting and dialogue. James Franco's best quality was that he managed to look less stoned and brooding than usual, which I personally appreciated (the stoned, brooding mysterious bad-boy thing never really did it for me). John Lithgow who plays Franco's father suffering from Alzheimer's also offers some touching moments, but his character is simply not given anything more than to be the face of the disease for the film. And while I was excited to see Freida Pinto in her first major mainstream role since "Slumdog Millionaire" she, like the other humans, was just not given much to work with and I was disappointed. Cast as Franco's love interest, she is nothing more than the pretty primate-loving zoo vet who wants to treat animals humanely; she is hardly given any lines and even her role of the love interest is lack-luster at best with her and Franco maybe sharing one sweet kiss in the entire PG-13 film. And Tom Felton essentially reprises his role as Draco Malfoy, only instead of rival wizards he is bullying apes. He did get the opportunity to deliver Charlton Heston's "classic" "dirty ape" line which fell flat and caused me to laugh out loud at its absurdity.
All in all I liked the film. It was enjoyable. As a science geek myself, I liked the biotech and gene therapy aspect of the film and that spin on how the apes rise to where they will end up; I'm a sucker for that complex ethical struggle that came from Franco's struggle to find a cure for his deteriorating father's disease and the unforeseen consequences. If you appreciate the quality of cinematic art then I recommend seeing the film simply for Andy Serkis's performance and the CGI; it's one of those performances that single-handedly carries an entire film and it's really okay.
