hm... I had the game Gray in the background.... the music from the title screen kinda fit the mood of the game. Open it in another tab, come back and play this game. I thought this game was making sound until I closed Gray and all the sound stopped.
As I play more, the bones really shouldn't stretch so much. Sometimes I make bones to try and limit muscle movement somewhat, but it doesn't work that way. The bones just stretch. For an example, see The Glider v.2 on my profile.