Anyone ever heard of Alien Legacy? It's a very old strategy game from 1994. It's not like any other game I've ever played, it's not really turn-based or real-time, it's sort of a mix between the two. It's for DOS, and you'll need DOSBox to play it. I just started playing it myself and it just blows me away how deep this game is. I mean, this game is remarkable. Best of all, you can legally download the game for free, since the Sierra released it as freeware. I highly recommend it, it's really fun. I welcome you to post here if you need help with the game or would like to share your thoughts on it, and I'll do the same. We can all help each other out. I've never actually beaten the game myself, but I heard it's about 50 hours long. Here are some links you may want to check out.

Full Game
http://www.abandonia.com/en/games/27...en+Legacy.html

Wikipedia
http://en.wikipedia.org/wiki/Alien_Legacy

DOSBox
http://dosbox.com/

Commercial
http://www.youtube.com/watch?v=A-b4dbdir3U