Lunar puzzle game?
I've completely forgotten the name, so let me give you some more info to narrow the search down.
It was a PC puzzle/mystery type of game... you start out something like disoriented on the moon or something and you have to run around (It's 3D, and I think the name has Lunar in it or something similar) and solve puzzles. There is an alien race there as well... and you are trying to get your space ship back to earth, and I think near the end you find out what happened that got you there, something about a murder happened inside the ship involving a gun or maybe poison.
I'm going to be amazed if someone actually finds the game, but I would recognize the name immediately after I saw it. I remember there was a wind-pipe puzzle, some sound puzzles, there are puzzles for the gates and such... I just can't remember the name.