F1ach: I seem to recall it was based on an alien that landed a spaceship on a planet, I also think it's ttile began with Z. He also used a gun iirc.
Woulda come out probably early 2000's.
Grargar: Zax: The Alien Hunter?
Cheers mate that's the one, it was bugging me all night :)
Klumpen0815: This is very relevant to my interests!
I just ordered a games compilation DVD with Archangel / Zax / Rim - Battle Planets / The Nations / Keep the Balance for a buck.
The only one there I recognised was Zax :)
If obscure isometric games is an interest to you, maybe try Gorasul :
http://www.amazon.com/Gorasul-The-Legacy-Dragon-Pc/dp/B0002KQX86 Got a lot of (imo) undeserved bad press at release.