Survivor pits one to four players up against a horde of Aliens, their numbers growing and more deadly breeds introduced as the wave number increases. It's a premise that's familiar from any blockbusting action game of the last couple of years, and Gears of War 2's Horde mode is but one of many examples of the art of gunning down ever increasing numbers of adversaries.

These elements come together best in C-Block, one of the two maps that's shipping with the game (two others will be available on release as downloadable content, free to those who take the plunge with the collector's edition). This is a level ripped straight from the most memorable moments of Aliens, taking place in the corridors of a colony that's reeling from an Alien attack.

There's the inevitable calm before the storm as the mode starts, and much like the Marine's single-player sections the tension is amplified by an assured use of light and dark; the space that initially stretches out before the player is inky black, and it's only the flick of the motion tracker that warns that something is coming.

Understandably, the first wave is relatively light; around five Aliens attack when playing solus, but the numbers ramp up according to how many players are involved. It doesn't make it any less terrifying, though, and even those opening moments aren't short on panicked fire and backtracking as the Aliens slither their way towards the player in any which way they can.

Pick-ups are dotted around in the form of ammo and stim-packs, though it's advised that some of the meatier arsenal that's lying around is reserved for a little later on - that Smart Gun comes in awfully handy around the time of the fifth wave when the more robust Warrior Aliens make their first appearance. After a handful of waves the C-Block opens up, a cargo door revealing another arena and a stairwell to defend. It's both a blessing and a curse, freeing the player from the confines of the initial corridor but making them all the more vulnerable to attack from multiple angles.