In 2011, Robbert Jansen, administrator of the Videopac.nl forum, was contacted by a programmer who developed Videopac games in the early 1980s. The developer gifted Robbert with several unreleased prototypes, one of which was labeled Terrahawks. This prototype, developed in Europe, turned out to be a completely different game than the Terrahawks that was actually released in Europe – a retitled version of the American-developed Attack of the Timelord. It's unknown if the unreleased Terrahawks prototype was passed over in favor of the Timelord release, or if it was meant to be a sequel. A sequel to Terrahawks was mentioned in a French catalog, so this is a possibility, but nothing is certain. The unreleased Terrahawks, while more similar in tone to the TV series it's named for, is more difficult than Timelord and Philips could have been less certain of its success.
In 2013, Classic Consoles Center created a cartridge reproduction of the prototype game, titling it Terrahawks: The Second Assault and assigning it Videopac #70.