> Well, the foreground was green and the tanks were simple sprites, not triangles, but
> we had a blast playing Scorched Earth in my student days. Could it be what you're
> looking for?
No, I forgot to say it was a top-down view (edited and enhanced the description a bit). I also remember Scorched Earth, I also had some fun with that one although the AI was crappy.
However today I finally remembered the name of a game I liked quite much around that time: XQuest. During all these years all I could remember is that it had something like 'crystal' in the name, and I found Crystal Quest which was the inspiration for XQuest. After some more searching and stubbornishenaniganism I finally found the name of the game. Simple but great.
Wound up, can't sleep, can't do anything right, little honey / Oh, since I set my eyes on you. / I tell you the truth.
I can't get it right / Get it right / Since I met you...