For Brickfete 2016 and the Friends contest, I made a Friends-ly tree slide GBC module. The input and output are to GBC standards so it should play nice with other GBC modules. During the event I had make various modifications and fixes. Although, it worked great at home. I think I got the bugs out of it now. It had pretty good response and feedback from girls and moms.
LEGO Friends Tree Slide GBC Module by dr_spock_888, on Flickr
Watch the balls climb up and slide down.