Halo is getting worked over. With Master Chief and Cortana in deep freeze at the end of Halo 3, the series – which has sold over 25 million copies worldwide and saved the Xbox 360 from the threat of Sony – continues by seeing the 26th Century through fresh eyes. As well as Halo Wars, the realtime strategy game already out, Halo: Reach, a prequel to Halo and an animated cartoon series, both out 2010, the next game to drop this month is Halo 3: ODST.

Halo has become a defining series for both Xbox consoles,” says Brian Jarrard of makers Bungie. “It’s a far bigger universe than the existing games and that leaves room for growth into new territories.” ODST are the mouth-mangling “Orbital Drop Shock Troopers” [1].

These sci-fi squaddies aren’t Spartan super-warriors like Master Chief – hero of the original trilogy: they work in teams, can’t jump or fall as far, and go for stealth over all-out action. But that doesn’t mean ODST is Master Chief-meets-Tom Clancy. Your crew starts out infiltrating the alien Covenant ship [2], but when you come to after crash-landing in a ruined city [3] it’s clear you’ve got other problems on your plate: you need to track down your now-missing teammates.

As a solitary trooper you can’t pile into combats with the gun-ho attitude of Master Chief, but this is hardly slow-moving stealth territory either. ODST sticks fairly close to classic Halo run-and-gun. A low-light, enemy-targeting visor lets you spot enemies in shadows [4]. But you won’t spend hours crawling behind cover – instead, strap on a low-noise pistol, pop a few headshots off, then peg it to flank the next cluster of Covenant. You don’t get Master Chief’s shield or regenerating health either, and can get knocked flat by grenade blasts [5], but the game remains more Halo than anything else.

The most obvious difference is in the story. The central city is the largest Halo level ever – and you’re free to pick the order of missions you take on. Complete a key mission and you’ll get a flashback to what’s happened to a squadmate – then get to play as them. Each has their own speciality – heavy weapons, sniping, explosives and pilot.

The other big difference from previous Halo games is the new multi-player mode. Throwing a big wink to Gears Of War 2’s ‘Horde’ mode, ‘Firefight’ [6] lets you and four friends cooperate to take on waves of Covenant. Survive long enough and enemies get tougher and the game ladles on extra pressure: plough through early waves and all Covenant suddenly get infinite grenades and good throwing arms.

The only concern is that the game isn’t very big – it was originally planned as an expansion pack, but Bungie are throwing in every multi-player map from Halo 3 on a second disc. That should be enough either way to write off your social life for all of October.

Halo 3: ODST, from £40, is out on Xbox 360 on September 22

Words: Simon Munk