Motion tracking/ face tracking

So recently, I ended up playing a game by the name of Portal, which some of you may or may not have heard of. It was actually released years ago, I'm just behind on the curve, but I absolutely love the games, and have become obsessed with the idea of making GLaDOS a reality on a smaller scale. It's been quite a few years since I've done any programming, so I'm not sure which microcontrollers are capable of what nowadays.

Is motion tracking / face tracking(or going a step further, facial recognition, which I don't think I've seen any microcontroller capable of) a possibility with arduino, and if not, does anyone have other suggestions for microcontrollers that could support things like this? Thanks for your time in advance.

A Raspberry Pi with a camera and image processing software comes to mind.

For Arduino, the CMUCam5 (PIXY) can track variously colored blobs.