It's my son's 3rd birthday in a few weeks and we already have the connectix Tile Marble run amongst other toys that we kept when my eldest out grew them. I was thinking of asking family to contribute towards a large pack of connectix tiles, that can be used to build things as well as extend the play of the marble run. My question is can the normal tiles be used to extend the marble run, or is there marble run extension pack that is needed? Thanks!