I Am Legend is one of those annoying ‘might have been’ films. It could have been great, but instead, because of either studio pressure or poor decisions made by the production, it falls short of its potential – the first part of the film is magnificent, but it falls apart towards the end.

I can put my finger on the bit where the film begins to nosedive. It’s great up until Robert Neville (Will Smith) has to kill his dog. Up until this point, the film is tense and tightly directed. But after the dog’s death, we’re introduced to another couple of survivors and we have to suffer some last minute attempts to find some ‘meaning’ behind the movie. Talk of god is introduced and the lean survival movie kind of gives way to blindingly obvious talk about tolerance and love.

We also have the female survivor say that god must have spared Neville, to which Neville rightly berates her, pointing out the fact that billions of people have died – the very idea that there might have been a ‘plan’ for this reflects badly on everyone. It demeans the plight of the survivors and says only bad things about the ‘creator’ that would have set this disaster in motion.

The end also suffers because we’re confronted with the appalling CGI for the infected people (or the ‘dark seekers’ as they’re called) – at the beginning we only get glimpses. Quite why they didn’t use people with make up, I don’t know. They surely would have looked better. But no, in a desperate attempt to create lots of kewl action, the filmmakers decided to make the enemy poorly rendered CG creations. Yes, freed from the constraints of live performers, you can have your bad guys climb walls and headbutt the pavement, but what’s the point when they never look real? Every time you see the dark seekers you’re taken out of the film. When they climb they look weightless, when they scream they look like a cartoon and all the other times there’s just an air of unreality. Just get real actors and cut back on the crazy shit. I’m sure people won’t spontaneously fall asleep if the bad guys aren’t constantly climbing lampposts like monkeys. There are other ways of making them threatening. You know, a bit of subtlety can work a charm.

The film also suffers from its tendency to indulge in cheap shots. There’s a bit where Robert Neville captures one of the dark seekers and tries to cure her of her disease. You’re just counting down the moments until she sits up and lets off a piercing scream, and like clockwork, she does. Then there’s the bit where Neville and his family, during a flashback, are escaping Manhattan when the outbreak first occurs. With the way it’s filmed, and with news of the crisis developing, you’re just waiting for the moment when an infected person slams against the car. And sure enough, they do. I surely can’t be the only one praying for some chills rather than laboured attempt at thrills.

But to be fair to the film, there are some nice creepy moments. An excellent example occurs when Neville’s dog is chasing a deer. The startled deer runs into a dark building and suddenly Neville has to possibly confront the dark seekers. He wants to turn back, knowing that they’re probably in the building, but he doesn’t want to leave his dog behind. So he has to wander the dark rooms with only a torch on the end of the gun to shine some light. It’s a very tense sequence, and it’s well constructed. And there’s an excellent moment when Neville shines his light into a room and we get a brief glimpse of lots of dark seekers huddled around in a circle, feeding. It’s a very creepy shot. And then the jump moment that soon follows once Neville finds his dog is actually well timed – unlike the other attempts to get a reaction, it’s not laboured.

Another favourite scene is when Neville is driving the streets and sees a mannequin in the middle of the road. You see, Neville, in order to still have some sort of human connection, talks to some mannequins in a video store. So to suddenly see one of them in the street is disconcerting to say the least. And Neville ends up losing the plot and shoots ‘Fred’ (the name he gave the inanimate object). He then begins to think he’s being watched and shoots at the windows. I wish that there was more of this. I wish that there was more of this confusion. But then Neville gets caught up in a trap and dangles from a rope and we quickly find out that this trap has been set by the dark seekers. The hunter has become the hunted.

But this scene kind of proves that Neville is wrong when he asserts that the dark seekers are no longer human. They’re still able to set up a trap for him and one of them even briefly braves the sunlight in order to voice his displeasure at Neville capturing one of his kind. Neville puts this down to hunger and social de-evolution, but maybe the guy is just pissed off that Neville bundled his girl into a sack. The alternative ending certainly suggests this. So for once we have a massive Hollywood blockbuster where the hero isn’t right all the time, which is pleasing indeed.

It also pleases me that a big action film like this can have a left of centre scene where the hero shyly eyes a female mannequin. It could be queasy in the extreme, but Smith manages to make it seem kind of sweet. His hero is pleasing mixture of incredible self-certainty and extreme vulnerability. I mean, if your family had been killed in a helicopter crash and you’d seen people get fed on by dark seekers and if you’d been in New York on your own for years, how long would it be before you started flirting with mannequins? I don’t think it would take long.

And Smith manages to put a lump in your throat when he has to kill his dog. And in the scenes that immediately follow. He says hello to the mannequin in the most pathetic way possible and then begs her to say hello to him, now that he’s all alone in the world. He just wants to hear a human voice speak to him. Smith is marvellous in the scene.

But unfortunately this high point signals the moment when Neville gets his wish and the film takes a turn for the worse. Smith begs for some human contact and then has to content himself with someone who doesn’t know who Bob Marley is. Be careful what you wish for.

Oh, and don’t think I didn’t notice the fact that Emma Thompson was responsible for this virus. Damn Limeys. They’ll destroy us all!