CAPX: It is attached to this tutorial, you can find it in the left column. I tried to make it as clear as possible with comments.
I exported 3d meshes in text format and used Construct 2 to project them in 2d, using sprites to represent each vertex. I simulate depth with scale and opacity.
Of course this is not real polygonal 3d, but more like in the early days, where you'd just scale sprites up and down to simulate their proximity to the camera.
While implementing a whole game using this technique would be possible it would not be easy. Instead of rendering meshes with many vertices, each vertex could be handled independently as a single object. You could then do a 3d space shooter or something like that.
Another usage is just for background animation, like a star field or in a menu.
At the time I'm writing this, the FPS drops in Chrome, but it seams to be a bug in the new version 32, it happens with all my project. So don't freakout if the FPS is low at the moment, I get much smoother results in Firefox while it's generally the opposite.
Left mouse button: hold to rotate the object.
Right mouse button: hold to move the object on the XY plane.
Mouse wheel: move object on the Z axis.
Middle mouse button: reset rotation and position.
Double click: morph to next shape (there are 5).