Giant Robo
Japanese title: ジャイアントロボ
Type: Special
Episodes: 1
Source: Manga
Genres: Action
Studios: OLM
Producers: Soft Garage
Duration: 4 min
Rating: G - All Ages

The pilot for GR: Giant Robo. However, there were significant changes between the pilot and the actual show, including a different writer and a different director. Thus, the special is less a promo for the series than an alternate version of how the series might have looked.

(Source: Orphan)