This is adorable. I know some people would say,"Hey, that's eloping!" Well this isn't just some Romeo and Juliet. (1) The game goes deeper than that, with the endless running mimicking commitment. (2) if it was shallow, then the "right" response to "How's Colin doing?" is jealousy. (3) They're birds, dammit! Let them literally leave the nest.
But yeah, the game has made me go awww~ It's simple but that makes it all the more amazing what multiple choice elements and runner games--both common--can do!