Good movie endings can do so much – they can make up for the film's other flaws like Be Kind Rewind or send you into a productivity-sapping four-hour Google hunt for the term "I'm finished" like There Will Be Blood. 

But bad movie endings feel like a cheat. And Will Smith's I Am Legend had one of the worst endings in living memory. We won't spoil the entire thing for you, but needless to say it may as well have been replaced with five minutes of a cigar-chomping movie producer in the shower sponging himself down with fistfuls of your money.

However, an alternative ending to I Am Legend has hit the internet. It's certainly different to the original – a bit less 'Will Smith is basically Jesus' and a bit more 'zombies have feelings too'. We're not sure if it's better or worse than the original I Am Legend ending, but that's only because the ideal I Am Legend ending involves Will Smith getting mauled to death by that lion 20 seconds into the movie. 

That is the nightmarish vision set out in I Am Legend, directed by Francis Lawrence (Constantine). Part sci-fi horror, part art-house stroll, the film is based on Richard Matheson's post-apocalyptic 1954 book about the last man alive on earth.

Thompson's character, Dr Crippin (why not call her Dr Death for God's sake?), has created a cure for cancer. Unfortunately for mankind, the 'cure' has a rather disastrous side-effect – namely, it turns 98 per cent of the world's population into corpses or super-agile, bloodthirsty vampires (who'd have thought it).

The remaining two per cent who are immune to the contagious disease – including Smith's character Robert Neville – naturally become food for the swarm of night-stalking bloodsuckers. Only government scientist Neville appears to have the ability to stay alive. But it's lonely at the top, as Neville discovers as he looks for a cure to 'the cure' amid the backdrop of a deserted New York.

Hunting for CGI deer in the middle of Times Square (no really) during the day and hiding in his house at night for three years certainly takes its toll on Neville, who with only his dog and a clutch of Bob Marley CDs for company unsurprisingly descends into madness.

He chats up mannequins; he learns all the words to Shrek; but, most surprisingly for the ever-chirpy Smith, he manages only one wisecrack throughout the entire film.

Another surprise is that despite its obvious similarities with 28 Days Later, I Am Legend is a far slower-paced and darker film. Rather more predictably, however, the over-use of CGI means Lawrence's post-apocalyptic New York is far more cartoonish than Danny Boyle's London. Indeed, the special effects overall range from the not-very-good to the plain pathetic. The only good bits involving the 'dark seekers' (Lawrence is at pains to suggest they are not vampires, despite the fact they suck blood and hate sunlight) is the parts where you don't see them. Not exactly a stunning endorsement.

However, Smith, despite clearly struggling to look miserable, gives a decent performance as the guilt-ridden scientist struggling to come up with a cure.

Unfortunately, like the film, he is all alone.

I am Legend is released on Boxing Day.

That's not exactly a surprise, since Will Smith could film himself puking down his chest into his underwear and it'd still top the US weekend box office. But the weekend box office success of I Am Legend proves that Will Smith can carry a movie completely by himself now – something that will come as a relief to his next two movies, the provisionally-titled Will Smith Pukes Down His Chest Into His Underwear and Will Smith Stares Unblinking At A Cinema Audience In Close-Up For Three Hours While The Word 'Obey' Flashes Constantly Underneath.

I Am Legend was always going to be a gamble for Will Smith, because it's a movie that lives and dies with him alone. But its gigantic success at the US weekend box office is a clear sign that Will Smith is now one of the biggest movie stars in the world, and that not only can he save the world again and again but he can even beat bad reviews. Speaking of which, a member of the hecklerspray staff went to an early screening of I Am Legend last week, but since it was in the UK he was banned from posting his review until Christmas Eve. So you've got one whole week to wait to see if I Am Legend is good or a dull cartoony waste of your time, as if you needed telling. Here's this week's US weekend box office top five…

1 - I Am Legend (Sadly not featuring the subplot from the book of I Am Legend where Will Smith falls in love with an infected zombie, despite the clear sequel potential of I Am Legend 2: I Am Legend And So's My Gruesomely-Mutated Semi-Zombie Son) $76,535,000

2 - Alvin And The Chipmunks (Well, what do you know? Massive-budgeted end of the world action thrillers really are more popular than cash-in animated comedies about mostly forgotten, deliberately annoying squeaky rodents who ram handful after handful of their own shit into their mouths for fun) $45,000,000

3 - The Golden Compass (Well, what do you know? Cash-in animated comedies about
mostly forgotten, deliberately annoying squeaky rodents who ram handful
after handful of their own shit into their mouths for fun really are more popular than Narnia rip-offs about polar bears smashing each others' jaws off for fun) $9,025,000

4 - Enchanted (Well, what do you know? Narnia rip-offs about polar bears smashing each others' jaws off for fun really are more pop… oh, bollocks to this) $6,004,000

5 - No Country For Old Men (Getting a much-appreciated weekend box office leg-up from all the awards it won last week. So at least now the National Board Of Review has a tangible effect on its winners – a 27.1% gross drop-off from last week. Hooray for the National Board Of Review!) $3,000,000

Read more:

Weekend Box Office – Box Office Mojo 

So what Will Smith needs to do for I Am Legend – more than with any of his other films – is sell it. Sell sell sell. Promote the movie as a thrilling romp that the whole family will enjoy. Exclude nobody in its appeal. And that's why Will Smith has decided to promote I Am Legend by giving a lengthy television interview all about how much Tom Cruise has taught him about the benefits of being a fully paid-up member of the Scientologists. 

Oh.

We've never been able to understand what Tom Cruise and Will Smith see in each other. Aside from a shared thermonuclear sense of self-confidence and the way they're both just a little bit too oversincere and laugh just one decibel too loudly to ever be convincing, we've never really grasped what the two of them have in common.

And yet it's there – Tom Cruise organised David Beckham's Welcome To LA party with Will Smith, and Will and his wife Jada were among the first people to see Suri Cruise when she was born. Why? Because Jada is a Scientologist and Tom Cruise has vowed not to rest until he's signed Will up, too? 

Don't be such a cynical bastard – that's absolutely not the case in the slightest. And to prove his point, Will Smith has decided to use an interview for his movie I Am Legend to tell the world how brilliant Tom Cruise is and all about the Scientology belief system and how you puny idiots will never ever even be a fraction of how brilliant Tom Cruise is at being a human being. Will told Access Hollywood:

“I was introduced, [to] it by Tom and I’m a student of world religion. I was raised in a Baptist household, I went to a Catholic school, but the ideas of the Bible are 98 percent the same ideas of Scientology, 98 percent the same ideas of Hinduism and Buddhism… When I sit and I talk with Tom Cruise, he is one of the greatest spirits that I’ve ever met – someone who is committed to making the world better. You have people [that] are attacking and wanna fight that don’t know nothing — how you gonna not know nothing about Scientology and attack somebody? It’s dangerous and it’s ignorant. How can I condemn someone for what they believe and I believe that God was born from a pregnant virgin?”

Let's just hope that Will Smith's Tom Cruise infatuation cools down a bit before I Am Legend is released because, while there's nothing wrong with defending a friend's religion – even if it's a religion that all of Germany hates – we can easily see how it could all spiral out of control and end up with Will Smith leaping around on a piece of home furnishing whooping like a faulty rape alarm. And that way madness lies.

Still, we're sure that Tom Cruise will be thrilled that Will Smith has leapt to his defence so publicly, although it's a relief that we won't be there when Tom and Will meet each other for the first time after the interview. After the first 45 minutes of hearing ever-harder high-fives, arm-punches and relentlessly-sincere cries of "You the man!" "No, you the man!" we'd probably start to get a little bored.

Read more:

Will Smith Defends Tom Cruise, Scientology – MSNBC