Rotate the cube with the left and right arrow keys. Rotate the cube up and down with the up and down keys. Press space to reset angle. Press C to open the shape selector. It has three shapes right now, "Cube", "Rectangular Prism", and "Pyramid". The left and right rotation is relative to the cube, the up and down is relative to a separate grid.
This took a while to make and I want to continue to update it (if I don't be lazy like I usually am). I am going to add more shapes and a custom shapes builder. UPDATE: New, improved, advanced 3D project in progress. Will put this one to shame. If I get around to finishing it, that is.