D-zone
 

I used to play this game all the time, but I can't remember the name at all! It was released in the late 80's or early 90's, I'm pretty sure, and the ships were triangles, kind of like in asteroids. There were lots of menus and stuff you could change settings in, and I think it was shareware. You'd fight in an arena kind of thing, and the screen didn't scroll, and you have to destroy the other ship(s?). You could buy different weapons and stuff, and some (or maybe all) used some ammo. I think it might have had rounds, too. I wish I could remember more, can anyone help?

Sounds a bit like D-zone: http://www.homeoftheunderdogs.net/game.php?id=3195

Aha, that's it, thanks. I guess it wasn't in space after all :P