Our 3D content creation pipeline is mainly based on Blender (www.blender.org). When creating a level we start with painting the level outlines and then in the second step place all the game elements needed, selected from our 3D model database. We wanted our level outlines to be as “blobby” as possible to visually fit the look of the game where a permanently rotating stick is moved around. Hence, circles and arcs are often encountered in our level design. For this purpose we have used Spiro splines (for more information on Spiro splines please check www.levien.com/spiro/). Our experience in short: Although numerically unstable, Spiro splines are very intuitive in practice and create visually pleasing results. In order to use Spiro splines in Blender we have ported the C implementation from Inkscape (www.inkscape.org) to a Blender plugin implemented in python. All 3D models used in “Why Does It Spin?” were also created with Blender. We have extended the Blender GUI to allow for adding different game entities (e.g., springs, gates, conveyors, etc.) along with all their specific properties. While advancing from level to level new game elements are introduced, and each chapter in “Why Does It Spin?” has its own style defined by specific decoration objects, colors and textures. We wanted the players of “Why Does It Spin?” to have fun exploring the levels and detecting all its details besides solving the level objectives.