Many video games I see appear to have the premise that it is played "once", over multiple sessions, going from some initial point to the end. Once you solve the last puzzle / defeat the last enemy / finish the "story", the game is done.
Civ, on the other hand, is designed to be infinitely replayable. Never mind the 16x4. I can always pick it up, and play a different game, and have just as much fun as the first game I played.
Of course, everyone is different. My son is constantly trading games back to the store, because he has "beaten" them. To each his own. :shrug: