Borek is right -- while game designers use the term "AI," they generally mean a pretty small set of techniques that are not really regarded academically as AI.
The reasons are not very exciting.
Real AI requires a lot of computing horsepower, and most video games run at 60 frames per second. There just isn't enough computing power available on a typical gaming computer to run something like a deep reinforcement learning algorithm side-by-side with top-notch graphics. Neural nets and graphics also compete for the same processor, the GPU. When game designers have to choose between jaw-dropping graphics and better AI, they generally choose the graphics.
Times will change, though. We're rapidly approaching the time when a cell-phone GPU can render photorealistic scenes at 60 fps, and we'll eventually have hardware so sophisticated that full-brain emulation is possible in real time. Maybe in one decade, and certainly in two.