The way it's used in the video isn't super-impressive - and it looks a lot like he already knew which memory cells to change, rather than using the memory interface to find them. It would also have been nice with an introduction to what the color changes mean.
But pretty cool idea, and I like how it looks. Seems a bit queer with a Mathematica interface, I reckon that it's limited how much of that program's power you can utilize when hooked up to an emulator. But if you're familiar with it, you can probably prototype things quickly with it