I really would love to give one of these a go as well, but the general consensus with various review sites was it takes time to learn how to use, as in, weeks of training. The other problem is that placement is key, if you don't have the electrodes in the right spot each time, it'll throw the readings off and produce unpredictable results. Not everyone's nerves are in the same place either, and the headband is fixed in size and placement, so some people will have more difficulty using it than others.
Typically, the best you could hope for is unique signatures for about 5 movements or actions, but you'll struggle with 2 to begin with. There's also the concentration element as well, since even talking will throw the readings off. Anyone who's been hooked up to an EEG and seen the readings in real time will attest to that. The device is largely a cool toy than anything practical, but even toy's can produce a great level of satisfaction, especially when you fire a gun in an FPS and kill someone, just by thinking about it....
Sorry, this isn't meant to be a review or anything, and since i haven't used the device and only read other reviews, i can only give an opinion (which is worthless to be honest, lol). But from those reviews, they all pretty much came to the same conclusion, it takes a long time to use and its results are unpredictable. I'd still love to try one though...