This is impressive work. If all of these earthworks are original finds on your part, you are indeed to be congratulated! But I was disappointed that your post did nothing to patch up the immense gap in my knowledge about the people who made these structures. I, for one, would be grateful if you could include either in your post introduction or the Description of your KML folder, a few words about the creation of these mounds, or at least a link to where I could read more about them. A photo or two, if you can find them, wouldn't be amiss.
I found information about the geoglyphs, which were discovered in 2007 and have been studied since then. However, the September, 2015, article states that "Reconstruction of roads has led to the destruction of the unique, gigantic geoglyphs located in Torgay district (Kostanay region), Kazakhstan." There is no information about which ones were destroyed and the GE imagery there is from 2013. That is pretty awful news.