I haven't made to it yet, but it seems like there must be a malfunction when the player completes the game or not. The previous version before music got changed didn't happen like that. Besides, you can see the next level but you can not advance to it because new levels haven't been released yet.
Oh yeah, I have noticed that, too. You can notice it in level 7485, where it supposed to be a winter land, but somehow it suddenly changed into a dinosaur-pie island.