Our time with versus mode was spent in environments we've previously played through solely as the survivors. In this case, the city streets and a hospital. Playing as the survivor side was familiar; we started off in a safe room, arming ourselves with automatic weapons, additional ammo, and health packs before heading out into the great unknown of zombie infested ... everything.

It bears repeating just how eerie this game is. It's downright nightmare fuel.

It bears repeating just how eerie this game is. Despite its over-the-top action and sometimes brightly colored set pieces, when it comes to the zombies themselves – and their swarms, oh the swarms! – it's downright nightmare fuel. It didn't help that our brains kept deciding to wait until zombies pounced before squeezing off a round or two, for whatever reason.

So, the premise of versus mode – as it is in the main campaign – is to (surprise) stay alive. But we couldn't stay alive while standing still. Sure, we may have taken out all of the zombies we could see, but if we lingered too long the game would send more. It's a mad, bloody dash to the level's end. Along the way, we found that simple tactics such as furiously lashing out with our melee attack when a Boomer had puked on us (more on that in a sec) was rather effective at keeping the intensified zombie swarm at bay. Alas, the survivors don't survive. The round ends and we become the infected. There are four types: Boomers, Smokers, Hunters, and Tanks – all with their own unique "hook." In the Boomer's case, it can vomit once and any survivor hit by its bile will attract zombies like crazy. Smokers can suffocate survivors with their tentacle-like tongues. Hunters can crouch to charge up a lethal pounce move. Tanks ... well, these "wild cards" are basically unstoppable for a period of time and deal serious massive damage.

It really seems like the ideal "pop on and play" Xbox Live experience.

The infected are one-off characters. Once you land their signature attack, you'll probably get blown away by a survivor. But, unlike the survivors, the infected respawn. We got to choose where, but not what we respawned as (we always hoped for the Tank).

There's plenty of opportunity to strategize as a team while playing on the infected side. In one instance, we worked it out so that the Boomer would vomit on the survivors and two of our hunters would pounce on them while the rank and file zombies swarmed in for a feeding frenzy. Our score multipliers went wild.

Ultimately, like the "main" game, Left 4 Dead's multiplayer is fast and frenzied – which is just fine by us. It really seems like the ideal "pop on and play" Xbox Live experience. There's not a huge amount of time investment required, but you'll be surprised (as we were) at how long it pulls you in for.