Just as movie trailers have become a crucial element in any film's marketing campaign, trailers for video games have become part of a new battleground to win the hearts and minds of gamers.
Killzone 2 impressed many at E3 2007
At E3 in Santa Monica, California, last week, new trailers for many of the most-anticipated games of the year were unleashed on to the public.
Trailers for two games in particular, Halo 3 and Killzone 2, are vital weapons for Microsoft and Sony in the struggle for pre-eminence.
Ever since the original Killzone was announced, it has been touted as a "Halo killer" and that debate continues to rage even though both games have moved on to sequels, and are running on next-generation hardware.
Any new information released by developers, from snippet of game detail to new screenshot and high definition video is discussed, debated and agonised over when it hits the net.
Ellie Gibson, editor of GamesIndustry.biz, said game trailers definitely have become as important as movie trailers.
"More and more gamers are online and used to using sites like YouTube and they want to see what they are going to play and not just read about it in magazines and look at screenshots."
Within minutes of release, copies of trailers spread across the net via dedicated game trailer websites and You Tube, and thousands of gamers pour over the pixels making snap judgements.
But trailers can boost hype and anticipation and, if done badly, can sound the death knell, said Ms Gibson.
"There's a real danger for publishers. In the past they could pick and choose which screenshots are released. But when gamers are demanding to see how a game looks and plays it's much more difficult; they have to be more honest."
In 2004, a trailer for Halo 2 raised expectations for the game, leaving some players disappointed when they finally got their hands on the title.
And two years ago the original E3 trailer for Killzone 2 caused a furore when it was discovered that the action was not being played on final PlayStation 3 hardware and was not genuine in-game footage.
Jaws dropped when the trailer was first shown as it promised a level of graphical realism and immersion never before seen in a videogame. Almost immediately interest in the PlayStation 3 console rocketed.
But that surge of interest quickly turned to bitterness when the truth emerged. Hardcore games website Joystiq referred to the trailer as "infamous", adding that it was "an unbelievable and completely improbable feat of gaming technology, quickly debunked as rubbish".
In an effort to repair the damage caused by the trailer, the developers, Guerrilla, launched a new trailer at E3 last week designed to win over the doubters.
It is almost identical to the 2005 trailer but crucially is running on finished PS3 hardware.
The first details of the Halo 3 campaign were shown at E3
"In many ways, the visual fidelity of the updated presentation matches the highly polished look of the debut trailer," said Joystiq.
"A critical eye could note a few rough jagged edges, and textures that are a far cry away from Hollywood renders," it added.
Ms Gibson said: "It was about keeping a promise. It was very well received; many journalists said they were surprised at just how good Killzone 2 is looking.
"It shows how much attention Guerrilla paid to getting that trailer right and showing off the game in the best light."
She added: "It looks like it's going to be great fun to play and is very cinematic and exciting graphically. On the other hand it does look like it's going to be another shooter, killing aliens and running around in a grey, industrial backdrop. We already have a lot of games like this."
The lengths that gamers and gaming website will go to in their analysis of trailers is startling.
Website GameVideos.com placed the original Killzone 2 trailer from 2005 in a split screen with the latest trailer to try and reveal differences. Frame by frame the video examines graphical effects and animation.
A similar forensic approach has been applied to the Halo 3 trailer. The games has been in development for three years but this is the first time that action from the single-player campaign has been revealed in detail.
"Halo 3 is arguably the most-hyped game in history," said Ms Gibson.
"People are expecting something very special and Bungie has very high expectations to live up to, and perhaps can never live up to.," she added.
On the highly popular Halo fansite, HBO, Claude Errera wrote: "Ever since the E3 trailer was released last week, I've seen occasional 'it doesn't feel right' posts describing the emotions generated by the trailer."
The quality of the game's graphics has come under great scrutiny and last week's trailer continued the debate.
One Halo fan on the HBO website said the way in which the trailer had been captured digitally had affected the look of the
"Why Bungie would release a video not at absolutely tip-top shape in terms of video compression is beyond me," he wrote.
But, one thing is for certain. The debate about both games will continued at a frenzied pace until September 25, when Halo 3 is released, and sometime in 2008 when Killzone 2 hits the shops.