Gears of War 3 debuts on Sept. 20. It will bring to a close the trilogy of sci-fi games that started in 2006 and has been played by more than 13 million fans of Microsoft’s Xbox 360.

Gears of War 3 is one of the most anticipated games of the year and it is Microsoft’s opening gambit in the big war for the hearts and minds of gamers that will take place this holiday season as the company competes not only against games from Sony and Nintendo but Facebook, Apple and Google games as well.

This new title will be geared toward both casual and hardcore fans among the 55 million owners of Xbox 360 consoles. Rod Fergusson, pictured left, the executive producer of the game, told us in an interview that this title is meant to be accessible to casual gamers, both with the single player mode and the multiplayer mode.

“You need to work together to get through it,” he said. “It’s the biggest campaign that we’ve ever done, and it’s the most polished too.”

But the game will also have some enemies that are extremely hard to kill. That’s because the game is designed for a four-person cooperative experience, where four players can fight the campaign at the same time and try to take on huge enemies together. Microsoft and Epic revealed the multiplayer game experience earlier this year, and they are finally spilling some of the beans about the single-player campaign today.

Check out our video interview with Fergusson below and be sure to read our preview of the game. We cover a lot of ground in the conversation, from the story of the game, the differences compared to Gears of War 2, the new characters and enemies, the accessibility of the title for new gamers, and how it was economically great for Epic to make all three games on one generation of console hardware.