Pretty nice concept, although it is not that different from the usual Metroidvania, except for the first phase where you cannot even go left. Visually, it clearly needs polishing (the animation of the sprinting dude was clever; maybe keep it simple and effective like you did there!), and the absence of sound is a bit unsettling. Also, the keyboard display is huge; maybe make it smaller, and only show the keys that actually have a role. Still, a great idea that, in my opinion, needs to be turned into a polished game. I would definitely enjoy a long version!