It’s proven gaming pedigree, star-studded cast and double-disc value aren’t the most impressive qualities of Halo 3: ODST, the Halo 3 expansion pack that has itself expanded into a full blown entry into the Bungie-born universe. It’s the fact that this love letter to Halo fans moved from conception to completion in a little over a year.

“I wouldn’t say we were flying by the seat of our pants,” said Creative Director Joseph Staten in an interview with ArsTechnica. “We knew it was going to be a modified version of the Halo 3 engine. We knew we had a smaller team, and we knew we had a year. From there we began to make plans.”

“With a totally stable engine, in the first three or four months, we realized we’re moving a lot faster than we thought we would,” he continued, saying that the team’s vision of the project, what they could accomplish and what ideas they could incorporate, quickly expanded. “We were actually going in too cautiously, and we were able to stretch a bit.”

And stretch a bit they did, with new missions, new weapons, new characters and new multiplayer modes like Firefight; the new wave-based mode combines the best of Gears of War 2’s Horde, Call of Duty: World At War’s Nazi Zombies and Left 4 Dead’s survival modes into a multiplayer experience that’s all Halo. And that’s all that matters.