DIY Yarn Wrapped Jam Jars - it's a good idea for the tunnel just to light the way. A solid row of these along the sides of the tunnel would be a good alternative to using whatever lights are built into it.
Display many photos with an old frame, wire, and clothespins. PERFECT use for the huge frame I just took apart for the girls hair bow holder! did before I saw. (instead use coloring for clothespins and frame! Glitta it up)