Few more days and the gamers worldwide will be able to get the most-awaited game of the year, Halo 3. The Microsoft’s $10 millions-marketing effort seem to live up to the expectations as everyone is preparing for the Tuesday’s big launch events in New York City, Seattle, Miami, Los Angeles.

Even the error of the UK catalogue retailer Argos doesn’t seem to be able to spoil the fun. Earlier this week the users of Eurogamers forums reported that they bought Halo 3 from Argos’ online stores.

The official launch date of Halo 3 in US is September 25, while the European release is schedule one day later, September 26.

Argo reacted quickly and issued a statement in which they explained that the unfortunate event was caused by an administrative error and they had no intention to break the release date.

"We are aware that a genuine administrative error has resulted in a small number of cases where Halo 3 has already been sold. We are currently ensuring that there are no further sales of this product in-store until the official release date, Wednesday 26 September. We have already taken steps to ensure that Halo 3 is unavailable on the Argos web site for reservation or purchase until the correct date.", Argos said.

According to GameIndustry.biz, Microsoft decided to not penalize Argos over their mistake

"I don't think there was any malice on the part of Argos at all, it was just an honest mistake. Argos reacted incredibly quickly to the mistake, they issued us with a detailed summation of why the mistake happened - mistakes like that, we have to be somewhat flexible," said Neil Thompson, senior regional director for the UK and Ireland at Microsoft's Entertainment and Devices division for GamesIndustry.biz.

Halo 3 is regarded as the biggest launch in the gaming history and Microsoft hopes to compete even with the movie industry.

"We felt this was a game that was the first of its kind that was able to move beyond just the video gaming hard-core and into a pop culture consciousness," Jerret West, Senior global product manager for Xbox Games, said.

So far the things are looking good as Microsoft announced earlier this year announced already that preorders in North America for the highly anticipated title have exceeded the 1 million milestone. Best Buy, GameStop and a bunch of other major MS partners for the Halo 3 launch have registered combined pre-orders that top 1 million units.

According to Wet, Microsoft hopes that Halo 3 release will be bigger than the opening $151-million weekend Spider-Man 3. Microsoft is confident worldwide sales could top $300 million by the end of its release day on Tuesday.

Halo 3 is the latest installment of a franchise developed by now Microsoft’s owned Bungies Studios. The first game, Halo: Combat Evolved was released in 2001 and since then, the game has grown into a global entertainment phenomenon, selling more than 14.8 million units worldwide, logging more than 800 million hours of multiplayer action on Xbox LIVE, and spawning action figures, books, a graphic novel, apparel and more.

Halo 3’s launch revolves around the number 3 and Microsoft thought this is a good occasion to triple its revenues by offering gamers three versions of the game.

The Legendary Edition ($129.99) will come out in limited supplies, being wrapped up in a highly collectible Spartan helmet case, along with two bonus disks full of supplemental content. The Limited Edition ($69.99) will also include a bounty of extras. Within a sleek metal collector’s case, gamers will also receive the first bonus disk found in the Legendary Edition, as well as a special “Halo” fiction and art book. For those who crave nothing more than the highly anticipated third chapter to one of the greatest gaming trilogies, the Standard Edition ($59.99) will consist of the “Halo 3” game.

The action of the game revolves around Master Chief, a genetically altered, cybernetically enhanced Spartan supersoldier, who must race back to Earth to stop the Covenant, a fictional militaristic alliance of alien races, first introduced in the original Halo game.

As Bungie Studios announced Halo 3 will be the last game with Master Chief as the main character, but the franchise will go on.

Microsoft already announced Halo Wars, a real-strategy game developed by Ensemble Studios and the famous Australian director, Peter Jackson, is working on a new trilogy inspired by the Halo universe.