Groombridge is a mysterious, white supergiant star at coordinates 996.0 : 904.2, at the end of the Rainbow Arrow. Orbiting it is a single planet, which is the final Rainbow World that forms the "point" of their arrow formation. Rumors have it that it once was supposed to be a rift in reality, allowing people to converse with two higher beings that are known by the mysterious names of FF and PR3. Whether or not these rumors are true, the planet, and the huge sun that it orbits, remain looming ominously.
There was supposed to be an easter egg encounter with the game's creators (Paul Reiche III and Fred Ford) at the Groombridge Rainbow World. The feature got scrapped due to Accolade's wish that the game was finished earlier. However, the art still remained. See