I’d only been playing BioShock for 15 minutes, and already I was trembling like a little girl.

Yet here’s the thing: For several years now, I’ve found that my favorite horror experiences aren’t coming from movies any more. They’re coming from games.

Why? Partly it’s because films have become much less artistically interesting. With a choice few exceptions — like the superb The Ring — I’ve found that modern horror movies have been offering less and less suspense, and more and more gore. Maybe it’s due to the rampaging success of Saw, which gave birth to the current trend toward torture-chic and metric tonnage of blood in scary movies.

In contrast, the best scary-game designers have quietly perfected the interplay of tension and release that makes for a truly cardiac horror experience. They have, in a sense, become even more faithful interpreters of the horror tradition movies than Hollywood directors.

In BioShock, for example, the audio editors are masterful at generating free-floating anxiety. As you wander through the game’s ruined city, whispering voices pan in and out of your skull. Often it’s the semilucid/semicrazy patter of the gibbering “splicer” humans, but either way, it makes you feel as nuts as they are.

Even worse is the sound of the ultra-Freudian evil-girl Little Sisters. Every time I’d stumble into a dark room and hear one of them say “What’s that sound, Mr. Bubbles?” in her chirpy, gargling-on-blood voice, the hair on my neck stood up. It was partly because, well, evil little girls are scary, and partly because I knew I was about to get my ass handed to me.

Indeed, the endless potential for ass-handing is why games may actually be a superior medium to films for scaring the bejesus out of you. The horror flicks of the ’80s always tried to generate a sort of proto-interactivity: all those terrified viewers, screaming “Don’t go in there!” at the screen, wishing they could somehow reach out and personally guide the Final Girl to safety.

In a game, of course, the fourth wall is obliterated, and you actually do have the choice about whether to go into The Bad Room or to run screaming. If you’re a total coward (like me) this ability to control your fate induces considerably more suspense, because I head-game myself into a frenzy. I’ll start down a corridor, hear something freaky up ahead, then freeze in panic. Maybe if I stay quiet the monster will go away? Shit, maybe it’s already headed this way, and I should move! But if I move the monster will hear me … so maybe I should stay quiet … gaaaaah!

Games already seem like dream states. You’re wandering around a strange new world, where you simultaneously are and aren’t yourself. This is already an inherently uncanny experience. That’s why a well-made horror game feels so claustrophobically like being locked inside a really bad — by which I mean a really good — nightmare.

Still, there are some interesting limitations on the form. I find that scary games almost always lose their scariness after about three hours. This is due to the inherent repetitiveness of games: After you’ve fought your 200th “splicer” in BioShock, you’re pretty accustomed to their gurgly ramblings, their patterns of attack, the boo-yah outta-nowhere teleportations. I was still tense, but no longer, you know, wetting myself.

The only way a game can continue to frighten you is if it constantly subjects you to new scary things, keeping you eternally off balance. But few publishers are willing to spend money on enough designer hours to churn out 40 hours of genuinely new content. Instead, they inevitably wind up recycling the same opponents, the same animations, and perhaps worst of all, the same audio cues. (The quickest way to ruin a scary mood is to have the monsters endlessly repeat the same two or three catchphrases over and over again; it begins to feel like telemarketing.) The best horror games — I’d include some of the Silent Hill and Resident Evil titles in this category — have come the closest to keeping things fresh as you play.