Alien: Isolation

A held motion tracker gives information a gameplay cost. The motion tracker is a physical tool in the character's hands, so using it means you can't hold a weapon at the same time.

It is an example of diegetic UI, alongside Dead Space's health on Isaac's suit and Metroid Prime's steaming visor. Quote: "Making this information diegetic can lead to interesting gameplay consequences."

The tracker shows what you can't see, feeding observe-then-move pacing. By revealing movement beyond the character's view, the tracker lets players study what's ahead and then act, the observation-then-execution loop at the heart of stealth.

Mark Brown groups it with Splinter Cell's optic fibre camera and Dishonored's lean. Gunpoint's Tom Francis calls information the raw material plans are made of.

Hiding what the alien can see and hear creates the fear. Alien: Isolation deliberately does not show the Xenomorph's perception, so players must judge light, shadow, distance and sound themselves and never know for sure whether they are safe.

Mark Brown contrasts it with Mark of the Ninja, which shows vision cones and sound pulses and makes the player feel like an apex predator. How much of the perception system you surface sets the feel. Quote: "A huge amount of fear and anxiety is derived from your shaky knowledge of the alien's senses."

An aggressive hunter AI fits because the game is about being hunted. The Xenomorph's relentless hunting suits a survival horror game, but the same AI would be wildly out of place in Batman: Arkham Asylum, where enemies must be sneakable.

The point is to judge AI by the experience it supports, not by how lethal it is. Quote: "AI must fit the game's intended experience."

Unlocking alien abilities over time makes it seem to learn. The Xenomorph gains abilities as the game goes on, so it appears to adapt to the player and stays interesting instead of becoming predictable.

Metal Gear Solid V switches on enemy counters at player thresholds. Enemies respond to repeated headshots, unseen base takeovers and night infiltrations with helmets, traps or night-vision goggles once the player passes a threshold.

Quote: "it's not actually "learning" - but it just won't do them until the player hits a certain threshold"

Dead Space's regenerating hunter was an early version of the stalker. The hunter regenerates and chases Isaac room to room through vents, breaking the rule that a cleared room is safe; it is described as an early prototype for Alien: Isolation.

The idea was borrowed from Resident Evil 4. Finally killing it gives "a real sense of catharsis".