Made as the pilot for GR: Giant Robo, this one-episode mecha action special ended up quite far from the series that followed. The full show brought in a different writer and a different director, so the special works less as a preview and more as an alternate take on what the series could have been. You are seeing a road not taken, a parallel version built on the same foundation. Mecha fans and anyone curious about production history will find it an interesting look at how much a show can change between its pilot and its final form. It was released as part of the GR: Giant Robo Millennium Box DVD set.