Am I the last horse crossing the finish line on this one?
Actually, don't answer. I'm pleased with my discovery. ^_^
Update: I've received suggestions for a couple other techniques for activating the snake game. The first can be found in the comments below. Note that this method can be tricky if you are working with a short video, or if your computer loads very quickly. I pulled up a 10 minute video, which was slower loading, and was successful with this longer vid.
Another suggestion, received via Reddit, was to pause, then hold down + left for a few seconds. This method does work, however, when the snake appears, it will be frozen in a downward, diagonal angle. You'll need to press left or up rapidly to unfreeze him and play the game.
Any of these three methods should allow you access to this YouTube easter egg!