The Riesen Panzer IV is an original design resin garage kit produced by NZ Industrial from Japan. The web site is all in Japanese but what I have been able to translate is during WWII the Germans set up a base on Mars. There they discovered some previous civilization's culture and technology. The engineers built armored walking suits based on this technology. After that I couldn't make much sense out of the machine translation. Cool looking stuff though.
I took some photos of the initial assembly but those are kinda boring so here is the finished model.