The Polycount Tower isn’t a contest. It doesn’t even have a goal, well, except for enjoying your craft as a 3D designer.
Powered by Sketchfab, the Polycount community of video game artists is going to build a tower one floor at a time. Just because they can. Artists are free to build whatever they want as long as they stay within the constraints of the size of one floor. See the announcement at the Polycount forum for full details on how to participate.