The Tone Rebellion by The Logic Factory
http://www.mobygames.com/game/windows/tone-rebellion
Man, just try to figure out what this game is about. It's by the makers of Ascendancy, my all time favorite game. But when I bought this when it was released, I was a bit disappointed. It just too strange and abstract. Its got floating islands, life forces, and some of the strangest aliens in any game I've ever seen.