"This is going to be a critical holiday for us versus Sony, especially on the console generation side, and they don't really have an answer for 'Halo 3'," Shane Kim, head of Microsoft Game Studios, said. "Given that, I suspect 'Halo 3' to drive a lot of Xbox 360 sales and Xbox Live memberships, I think at those midnight (launch) events, there are going to be a lot of people walking out with an Xbox 360 along with their copies of 'Halo 3'."

Halo 2 earned $170 million in sales within first 24 hours and had 1 billion hours of online gaming. Now let's see how much money Halo 3 will earn. Its regular edition will cost $60, two limited editions will cost $70 and $130.

Gamers can download Halo 3 from Microsoft's Xbox Live. Halo 3 public test has already launches, but gamers report troubles while downloading it and joining existing players.

"We know that we have a lot of fans that have been waiting for the beta for months, and even took time off of work to start early today. We really appreciate their enthusiasm, and we hope the small delay won't dampen everyone's enjoyment of the game," said Microsoft's representative.

By Ruzan Harutyunyan for HULIQ