3D graphics is really strainfull on computers, and besides, whats the points of making a platformer 3d? It wouldn't be a platformer anymore because it'd just be a waste of a computer's resources. If there was a 2d game to a 3d game it'd be best to just take pictures of the 3d models (for each frame of an animation or something) and then import those pictures into flash to have the appearance of 3d graphics but not take up the resources a 3d flash game would.