The only sign of real-time strategy title Halo Wars at PAX comes during Graeme Devine's presentation of the game during the show.

But that doesn't mean the game's not moving along.nicely. In fact Devine, lead writer and a designer on Halo Wars, said that it will be playable at next weekend's GameStop convention in Las Vegas. Perhaps it will even make an appearance at Tokyo Game Show.

And Devine is itching to unveil more about the game, specifically about the story he's written for it.

The events of Halo Wars take place twenty years before the original Halo and center around a band of humans and their ship, the Spirit of Fire.

"Because it's a strategy game you play as more than one person," he said. "You want a broader story with more than one character, an ensemble of characters."

"It was cool to be able to write about more than Master Chief."

Of course the game's prequel story still has to fit into the canon of the Halo universe, a canon still maintained by Bungie.

"There's lots to learn in the canon and you have to learn to respect it." Devine said.

But that didn't prevent him from getting creative with the universe, even creating a whole planet to invade for the game.

"I did a whole planet, Arcade," he said. "I made up a press guide for the planet as if they were trying to sell themselves and I sent it off to (Halo writer) Joseph Staten."

Staten ended up OKing it and even including the planet in Halo novel Contact Harvest.

The story of Halo Wars unfolds during a time when there is more than on Spartan, he said. "There are lots of Spartans and the covenant aren't in a civil war, they're just evil."

The story, which ties together the battles of the campaign, is completely finished. But Devine said he is still working on lines of dialog and battle chatter.

Creating the weapons for the game, another thing that needed canon approval, was fairly simple for the Covenant, he said.

"The covenant were pretty much finished off, but in the first person shooter the Master Chief was the one all powerful army. So we had to build more into the humans to make them a balanced army."

While Halo fans can be unforgiving, Devine thinks that plenty of them want to see the more of the Halo universe.

"I think there are people who want to play Halo from a different angel," he said. "They are excited to see that universe expanding a bit.

Devine also worked on the control system for the console-based real-time strategy game. A system that he thinks solves the problems that other console RTS have run into in the past.

"I really think we have cracked that nut," he said. "We look at all of the (control systems) for console RTS games, the one we learned the most from was Pikmin. That was a very good strategy game."

As the team continued to modify the controls Devine said the game got to the point that playing it with a controller was easier than playing with a mouse and keyboard.