Thanks!
I chose the repeating level because I thought it made the puzzle more interesting -- forcing the player to think differently about the same setup. Oh, and of course it cut down on development time too. :)
Not looping the music was a choice. It ends roughly at 6pm and the sky is much darker by then. But your comment makes me realise that perhaps a different track, or just some ambient wind noise should start playing at that time.. so you know you're playing after the buzzer (so to speak).