The biggest problem that I can immediately see is that in the original Knightmare series, the player was spatially and proprioceptively aware; they couldn't see the room around them, but they could use themselves as a reference point, so things like "turn round 180 degrees" or "take one sidestep to the left" were possible commands because they knew where they were now and where they had to end up to obey the command. With a game, you have no reference points other than those the game's giving you, so you can't judge 180-degree turns, or how many steps you've taken; you have to rely on holding the button for a certain amount of time, and even then, it's a very narrow window (say, the difference between holding for half a second and holding for two-thirds of a second, which isn't easy to estimate if you're not practiced at it). Even "keep going until I say stop" is hard to make work, because of the delay between the guide saying it and the player hearing it, processing it (hopefully accurately) and then acting upon it. A calibration and practice period would seem to be the most useful way of building a base to work with... but then there'd be less to laugh at in the videos when it all goes horribly wrong. :P

D.F.