At first, I see nothing - only darkness. But I can hear the people around me shifting their gear. The sound of metal on metal - bullets loading into chambers. A man speaks in what I recognize as an Eastern European language.

*DING*

"No Russian," reminds an unknown voice, in English.

*DING*

The scene fades in and you realize you're in an elevator, surrounded by well-dressed, heavily armed men. You are also holding a fully automatic machine gun in front of you, a fresh chain of ordinace at your disposal.

*DING*

The elevator doors open and you all file out into the open. You realize you're not in a military complex, as the heavy weaponry might lead you to expect, but inside an airport, and there are hundreds of people standing before you, waiting to go through security.

As you exit, the men form a flanking semi-circle around these men and women, with you at their center. An airport policeman turns to face you and the rest of the crowd follows suit. Before the policeman can draw his gun, before anyone even has a chance to scream, then men around you start mowing down unarmed civilians.

I hesitated for a moment, shocked by the massacre, appalled at what the game was asking me to do...

And then I opened fire.

A sick feeling crept into the pit of my stomach. These weren't real people - merely digital fascimiles. I've slaughtered thousands of digital beings during my lifetime as a gamer. But those were 'bad guys': humans and creatures set decidedly in opposition to my characters goals and values. The men and women before me were 'innocents,' literally caught in the crossfire of one crazed man's war with the Western world.

I plodded through the level, assisting in the slaughter, all the time rationalizing -

"This is just a game. This is what the game wants me to do. I'm an undercover agent. I'm doing as I was ordered."

Modern Warfare 2 is not the firstgame to make me feel guilty. In Prey (2002) I was forced to kill my girlfriend Jen after searching for her the whole game. The aliens who captured her had spliced her with a horrific monster, and it's the only option to progress the story. Even though it was a mercy killing, I still felt pretty horrible about it. Afterward I was even more determined to kick some alien ass.

The single-most disturbing game I've played is Tale of Tales' The Path. Described as "a short horror game," this isn't Resident Evil-type scares, e.g., dogs jumping through windows. The Path stretches the limits of what a game can be, an orgy of symbolism based on Grimms' tale of Little Red Riding Hood.

The player selects one of six "Reds" and is told to stay on the Path, and you can. It will result in a safe and peaceful journey to Grandmother's house. Stray from the path, and you invite danger. Once you've lost sight of the path, you'll never find it again on your own. If you find your "Wolf" while wandering about in the woods, you'll black out. When you come to, you'll be unconcious in the mud in front of Grandma's house. Some of the girls' Wolf encounters hint at rape; others', less sinister things. But depending on your exploration of the woods your first-person trip through Grandma's house will be a complete mind-fuck. After my first play-through I sat in stunned silence at the "SUCCESS" screen, a sense of utter dread hardening like cement in my chest. Now it was time to pick the next sister, and send her to her doom.

Doing battle with Gigyas in Earthbound (aka Mother 2) scared the bejeesus out of me. His multiple forms, his random babblings, his ethereal and seeming immortal nature; I get anxious just thinking about that final battle.

The strategy for defeating him is such a wonderful bit of game design. Paula's prayers work at first, but then start vanishing into the void. You have to persist in your prayers to defeat the ultimate evil and they end up involving the player, calling him by name (you input your name at a much earlier point in the game). WOW.

The rest of Modern Warfare 2 often feels like they took too many pages from a Jerry Bruckheimer script. But that early (and controversial) level produced an emotional reaction often absent from high-profile big-budget releases. Snow mobiling while shooting with one hand is pretty cool. But the most memorable moments in games are those when you feel like all hope is lost, when you feel like you've been completely forced out of your comfort zone, and when everything is not as it seems.

See also: Eternal Darkness: Sanity's Requiem/Sanity effects