Also a classic computer game from Novagen Software for the Atari ST and Commodore Amiga. It was released in 1990. A PC version was completed but never released to the public.

Like the 1989 game 'Starglider 2' from Argonaut Software, it featured solid-filled polygons and a complete solar system that you could explore. Unlike 'Starglider 2', you could actually get out of your vehicle and wander about.

This is why it's so memorable - you could fly from one planet to another, find a city, explore, and fly back again, all in one continuous sequence. Only Frontier has managed to capture the same feeling of freedom.

The plot involved preventing the comet of the title from impacting on a planet called Eris in a distant star system; as with the prequel, 'Mercenary', there were several (five, in this case) different ways to achieve this.

Some of the solutions involved blowing up planets or the comet itself, whilst two of the solutions were more esoteric and involved finding a magic wishing crystal, or the author's computer, with which you could crash the game.

There was a sequel, 'Mercenary 3'. Nothing has been seen like it since.