Yeah... I'm with Altourus here, it's totally fine to have forms and whatnot, otherwise this challenge would get very sparse entries. Anyways, this is a very neat piece. The animation is great.
I took that to mean not actual objects, not shapes. Where would we draw the line with that. Is a line or circle an issue? Or is it anything that apears 3 dimensional?
Is this not an abstract painting because we can recognize squares? http://arts-entertainment.m-karam.com/what-abstract-painting-is-all-about/