CGmadness 2.1.1 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Games, more precisely Arcade. This free software for Mac OS X is an intellectual property of Sven Reinck. We recommend checking the downloaded files with any free antivirus.
From the developer:
CGmadness is based on the classic game Marble Madness. It is running on OpenGL and uses current CG techniques like light maps, bump-mapping, and reflection shader. It also has an editor where you can create your own levels. If you want to share the level, you can upload it.
You may want to check out more software for Mac, such as Detritus, SwordEdge or DotBot, which might be related to CGmadness.