I haven't found anything mechanically similar (yet) but I have found one other game that shares a theme.
Single Sighted (mine) and One Pixel both use "only one pixel" specifically referring to the viewport size. Mechanically, however, they couldn't be further apart - mine is a simple exploration game while One Pixel is a precision platformer. I feel like 1x1 viewport as a theme could be diverse enough for a whole game jam itself.