I think that Space Duel is way under rated. It's simply a great vector game. I used to play it in the arcades bitd and it was one of my favorites. Too bad I'm not nearly as good at playing now as I was back then. I have 3 Space Duels, 1 restored, 1 converted to BW, 1 converted to Major Havoc. Now I'm working on a repro Quantum to go alongside them. All are great classic games.
Bill