The Game Boy: Headcrabs, Deathclaws, and Bears – Oh My

BioShock, meanwhile, designed an entire ecology around Big Daddies, making them far more than diving-suit-clad foils for the business end of your shotgun. Over the course of the game, you discovered their origins, purposes, and – eventually – became one yourself. (Admittedly, however, it wasn't until BioShock 2 that the franchise really perfected that concept.) Sure, having a giant drill for a hand definitely gave the Big Daddy an upper hand... drill... thing in the memorability category, but a gradual trickle of information turned Big Daddy from a giant target into a crucial part of Rapture's existence.
There's also the matter of smart, measured build up and the air of mystique it creates. Wasteland denizens in Fallout 3, for example, whispered of Deathclaws in frightened tones long before I ever met one face-to-face. And when I finally saw one loping toward me, gangly limbs flying like vital-organ-seeking missiles? I turned tail and fled for dear life while attempting to write out my last will and testament. Lamentably, I didn't exactly make it far.
Indie horror hit Amnesia, however, really steals the show in that category. It's so terrifying not because boogie men pop out and shout “boo!” around every corner, but for the exact opposite reason: they don't. Instead, there's a constant sickening dread lurking in the darkness. Slight sights, unsettling sounds, perfectly placed shadows. Together, they create a mystique that other survival horror games simply can't match. And your character, of course, is hopelessly helpless, rendering the classic “fight or flight” multiple choice test fairly easy. The answer is D) Wet Yourself.
There's another factor, though, that I think has played a major role in the shift away from interesting, well-designed enemies: graphical fidelity. Madness, you say? Well, consider this: The more realistic graphics are, the easier it is to design enemies that look and move like people. However, as humans, we naturally fear difference. My poison headcrab phobia? I bet it wouldn't be nearly as bad if I wasn't also violently afraid of spiders. Point is, we're pre-programmed to fear things that are unlike us, because nature's creepy crawlies have a tendency to, you know, murder us with poison.
Earlier games, though, were perfectly positioned to take advantage of that. A lack of detail became creepy, inhuman abstraction. Awkward animations became herky-jerky, unnatural movements. Enemies like Legend of Zelda's life-sapping Re-Deads and dungeon-crawling (literally) Wallmasters were – on some level – a product of necessity. Technology was limited, so developers had to be creative.
Ever played SkiFree? Yes, that SkiFree. Same idea. The yeti didn't trigger minor heart attacks just because it signaled insta-death. Its rapid, oddly terrifying movements gave Child-Me many a pixelated nightmare because it ambled ever forward in a manner that was downright wrong. Happily, Minecraft's enemies – Creepers, especially – carry that torch today to some extent today, but they're the exception, not the rule.
By and large, it's all hyper-realistic terrorists this, hyper-realistic zombies that. Oh, and there's the occasional hyper-realistic giant spider in there – just to make me feel frightened in spite of myself. I want more than that, though. Give me a love-hate, life-death relationship for the ages – not another shooting gallery. Press start. Find me a new challenger.