[warning: There are Braid spoilers here, increasing as you go along]
[real spoilers from here on]
I love that its several stories at once, all overlapping and informing each other. The whole relationship gone sour and how regret colors our perception, and how you can be the bad guy in your own story - all this would have been greatness on its own. It really goes to the next level with the atomic bomb, and somehow making an analogy between seeking the princess and seeking scientific discovery.
Time, regret, loss, and a bitter lesson possibly learned.
And its all there in the soundtrack, which is what drew me to this game in the first place.