Zero War

Despite an interesting premise, Zero Wars just isn't much fun to play and travelling up and down those samey corridors soon gets monotonous. I think it's partly the lack of control you have over your driving (IIRC limited to which junction you wanted to choose) that gives it a somewhat "pointless" feel.
I remember the publishers Harlequin coming out with some very ambitious plans to convert "big name" games from other formats, but they never got that far. Still, they put their money and effort where their mouth was in what was then becoming a very hostile market for 8-bit Atari software, and for that they deserve respect- shame it didn't work out.