Intriguing idea. Reminds me of audio only games like Papa Sangre II in that there are similar challenges to face where you pretty much can't see anything. However, I kind of have no idea what's going on and just fumble around a lot until I get to the goal. I mean, I understand what I'm supposed to do -- but it's definitely hard to get feedback on what's going on without having a sense of what jump height is like, what the world could look like, how movement works, etc.
Perhaps a way to fix this is by starting with a full resolution platformer, and then slowly over time making it more and more pixelated until it all is one pixel. By that time, the player might understand how the physics works to really be able to play it.
Still, as an experiment in minimalism alone, it's an interesting specimen.