I love that about it, conceptually (having never played it)... an infinite, or effectively infinite, game. The idea of being able to explore the universe, other stars and galaxies, is one of the most exciting and appealing ideas I've ever thought of (and I've been thinking of it my whole life). The whole idea of a universe simulator, even if a game-based one that obviously can't even touch on the complexities of the real universe, is so fascinating to me.