Summary of controls and interface for the confused:<p>Paint on the gray grid to toggle the existence of pixels. You put your mouse where the top face of the pixel goes. Change the color of the pixel to paint by selecting a color from the bottom-right.<p>Move the gray grid up or down to edit a different layer/level. Pixels above the grid are hidden. To move the grid, drag the slider at the left, click its arrow buttons, or use the mouse wheel.<p>You can rotate the camera by dragging anywhere in the canvas except for the gray grid.
There's also Cubescape (<a href="http://www.themaninblue.com/experiment/Cubescape/" rel="nofollow">http://www.themaninblue.com/experiment/Cubescape/</a>) by Cam Adams.
Snarky remark, but:<p><<Over Quota<p>This Google App Engine application is temporarily over its serving quota. Please try again later.>><p>So much for the "infinite scalability".
Why does the perspective of the drawing grid appear to get wider as it gets further away?<p>edit, to answer my own question: it doesn't get wider, it just doesn't shrink into the distance either. It still feels odd not having perspective.