Nothing to do with games at all. I made a sword, then a shield to go with it, then the knight to "hold" them. But I didn't feel like making legs so I gave him tank treads instead. Artistically, it's a style that I've not done in a long time but back in my teens I would do this frequently; "sketch" something out using layered polygons. It's fast, easy, and forces you to think of the components as their shapes and silhouettes.
The animated square actually is game art related, to a degree. I was thinking what it would look like to take pixel art and animate the pixels by moving them around rather than changing them. Imagine like Transformers (the old toys are particularly apt for this purpose - rather than the recent movies). You could have the pixels of a space-ship break apart, shifting and spinning around until reforming into a mech using only the same, original pixels. Obviously you have to work with higher resolutions than the apparent design consists of (this 5x5 "pixel" square is made of 8x8 per "pixel" for example, IIRC) and the movement would be better if you used squares in a vector art program like Inkscape; which I did.