Tonka's GoBots began life in Japan as Bandai's Machine Robo toyline. After achieving success in the Japanese market, Bandai decided to export the Machine Robo toys to the west using Tonka as a domestic licensee. Beginning in 1983, Tonka marketed the toys as GoBots: Mighty Robots / Mighty Vehicles in the US. Each figure sported a name (as opposed to Bandai simply naming by the alternate mode), an allegiance to either the heroic Guardians or evil Renegades, and all-new package art.
The earliest GoBots were sorted into two categories: either “regular” carded figures, or Super GoBots. The “Regular” GoBots were based on MR's “600 series”, so named for the 600 yen price point (about $2.50 at the time). Super GoBots were sourced from MR's “Scale Robo” and “Big Machine Robo” sublines. All of the designs in these classes used die-cast metal in varying degrees, and often featured chrome and rubber tires. Many of the designs were closely based on real-life vehicles, while others were futuristic. Some of Tonka's later offerings were based on World War II fighter planes. Most figures did not include any accessories, but some had detachable weapons, most often seen with the larger Supers.
The line eventually expanded to include two combiner teams (sold individually or as sets), combining battle armor, and larger motorized figures sourced from other Bandai toylines. Tonka included several of their own offerings. Most of these were vehicles or playsets for the regular figures to interact with. The Tonka designs are notably less intricate, all-plastic, and often electronic. To meet the growing demands for more transforming robots, spurred on by rival Transformers' success, Tonka licensed Arco toys under the GoBots brand. The Arco toys were mostly redecoed from their own series, Ro-Gun. They appeared totally inconsistent with the other GoBots entries, but sported large GoBots logos to associate them with the main toyline.
By 1987, the sales peak of Transformers culminating in their animated movie hammered the last nail in GoBots' coffin. Despite outlasting its predecessor series, Machine Robo, the GoBots franchise could not withstand the onslaught from its main competitor. Designs toward the end of the line were not released in Japan, and saw only scarce availability in the US. Many of these toys saw much wider releases in Europe, where the end of Robo Machine: GoBots came later than the domestic Tonka line.
The GoBots legacy is a mixed bag, and highly subjective. While many collectors view GoBots toys as inferior to Transformers, Bandai-produced models retained many qualities popular among Transformers circles until the end of their run. Transformers dropped traits like chrome, die-cast, rubber, and realistic alternate modes as their success drove sales higher. It could be argued that GoBots lost out because of a lower-quality TV series, or that GoBots competition caused Hasbro to push harder for Transformers' commercial success, with traits like Tech Specs and rubsigns. Either way, when Hasbro acquired Tonka Corp. in 1991, they also obtained all rights to domestic GoBots intellectual property, and have been using the brand name for many purposes ever since.