The new Locust are fantastically varied

No longer is Gears of War just about machine-gunning the grunts to death and saving the rockets for Boomers. Every new Locust requires a new tactic.

Kantus healers do exactly what their name suggests, appearing as a support class for their brethren with the ability to resurrect Locust troops. The appearance of these guys instantly shifts the focus of a battle, making them a priority target. Tricky when they intelligently make a point of hiding behind their allies, forcing sniping and other long-range tactics.

There's also a huge, troll-like Locust which attacks purely with melee tactics, swinging an immense mace and blocking fire with an almost head-to-toe shield. It needs to be killed from a distance as it's absolutely lethal at close range.

And the small but deadly Wretches are joined by an enemy called the Ticker. These diminutive, dog-like creatures are rigged with timed explosives and run straight towards the Gears before sitting down gleefully at their feet to explode. They're essentially moving landmines, and their sheer speed and numbers make them terrifying. At one point we had to face off against a whole swarm of them in an unlit tunnel with barely any cover. Needless to say, a very fast trigger finger was the only way to survive.

Finally, and typifying Gears 2's more dynamic approach to the enemy, is new head bad guy Skorge. If Raam was Darth Vader, this guy is Darth Maul. His first appearance in a cut-scene towards the end of act one was as awe-inspiring as it was intimidating. Leaping and flipping around with ninja-like speed and precision, his double-ended chainsaw staff is going to make him one hell of a challenge to take down. We're revelling in and fearing our inevitable confrontation with him in equal measure.

Sera is now a living, breathing society

While the isolation faced by Delta Squad in the first game did a good job of evoking the mournful desolation engulfing the human race, there was very little tangible sense of a real war going on. Humanity's plight felt less like a struggle for control of a planet and more akin to the desperate survival attempt of a few lonely individuals. All of that has changed in Gears 2.

From the opening scenes, we're thrown deep into the wider reality of Sera. We meet up with Marcus and Dom - both now celebrated military heroes of the human campaign - in a hectic military base on Jacinto Plateau. Troops and vehicles swarm around the place, and a sense of organised chaos abounds. The scene left us in no doubt that this is a global war affecting every sentient being on the planet.

The opening level really drives this home. Fighting alongside new allies from the human forces in order to push back a Locust invasion of a hospital, Marcus and Dom were constantly connected to the city they were fighting in. We heard the wider battle raging on just outside the building. We even saw it when fire from a human gunship tore apart the hospital windows, drawing our attention to the swarms of Locust piling into the streets below. And as will be the case throughout the game, we found several Resident Evil-style letters and log entries written by unseen characters, detailing the wider human story of the war for Sera. Everything's bigger, but we felt a lot more in touch with it than we ever have before.