Insider's guide: Halo 3

LONDON, England (CNN) -- A new video game, so what?

You're obviously not a hardcore gamer, but even those people who wouldn't know an Xbox from a shoe box can't have failed to miss the launch this week of the most eagerly anticipated video game of the year. And for a change it's not just hype: over one million games were pre-ordered months before the game was released on September 25.

It took 300 games developers three years to complete it, but when it comes to raking in the money, Halo 3 has already proven to be an even larger cash cow than Hollywood's biggest blockbuster, Spider-Man 3, making an incredible $170 million for Microsoft, the games' producer, in the first 24 hours of sales. As gaming columnist Marc Saltzman said: "This is as big as pop culture phenomenon get." Police in London had to cancel the proposed launch party in Oxford Street for fears that they wouldn't be able to control the crowds. It's also become more than a game, spawning novels, comics, action figures and there are whispers about a top-secret project with director of the "Lord of the Rings" trilogy, Peter Jackson.

So what's the game about? Shooting aliens and saving the world, I suppose?

Err, yes, at it's most basic level. As the third and final part of the trilogy you take the role of futuristic super soldier, Master Chief, and together with a band of space marines you have to battle alien creatures hell-bent on destroying humanity. But there's much more to it than that. Reviewers have remarked on the incredible attention to detail in the graphics and there are over 39,000 lines of dialogue, so its more than just a glorified point-and-shoot game. It even has a Hollywood-epic musical score to help players feel completely immersed in the experience, plus non-interactive clips that look as good as any sci-fi film.

You can also play against other Halo-heads online. The Xbox 360 games machine allows you to play against or with other gamers connected through the Internet -- more than four million online games of Halo 3 were logged in the two days after the game's launch. But you might also want to stay away from the Internet for a little while; spoilers showing the end scenes of the game have already appeared on youtube.

Actually it sounds pretty good...

Imagine your disappointment then if you were one of the fans of the game who eagerly received their copy, complete with limited-edition tin that included a replica of Master Chief's helmet, only to find the disc scratched. Gamers have reported that the game still plays, but it's a bit of an embarrassment for Microsoft, whose Xbox 360 has been beset by problems. In July, the software maker said it would spend more than $1 billion to repair broken Xbox 360 consoles and in August it disclosed that some Wireless Racing Wheel game controllers were overheating and smoking. Despite billions of dollars in investment Microsoft still hasn't made a meaningful profit on its video games machine.

So it's not just about saving the world, but Microsoft.

Well, the Xbox 360 certainly hasn't been as popular as the Nintendo Wii video games machine, but let's not be too concerned about the finances of a company with an annual turnover of around $50 billion; this is about escapist fun, not profit margins. E-mail to a friend