Mine came in a DVD that you buy at the store and use at home. I wonder if that makes a difference.

I have lots of 3D glasses! Saved from many of the 3d movies I use to take the kids to. Then you could keep the glasses. It's a good idea but I don't think kids will care enough to wear the glasses to see it after the first view. All the kid movies are 3D now and it's nothing new to them.