Actually, I remember playing Mass as a child. We used potato chips for communion, and we did the whole thing with the prayers and songs. It was all innocent, just fun to do. We were around seven years old, my classmates and I, but it felt important and fun, all wrapped into one.
My children play Mass occasionally, too. They absolutely love playing Bible stories, though. Of course, David and Goliath is a favorite. Preston (my husband) even joins in sometimes as Goliath, and his death scene is unbelievable. Oy. When I do laundry, they take the folded towels, unfold them, wrap them around the house and go around pretending to be Mary and Joseph.
If it's done in the spirit of fun and sweetness, it seems all right to me. When I read the biography of Teresa of Avila, she mentioned playing Mass all the time with her brother.
We played Mass too. Used Necco wafers for Communion ;-)
Oh yes, we played Mass! We used white bread that we squished to be flat. And, we did this before we had made our First Communion, so we knew that Communion at church was different (Body of Christ) then our white bread. We also did the whole picking of readings from the Bible and songs for our Mass. Funny thing, I can't remember what we did about the Homily!
We also used to put slips on our heads and play like we were nuns.
Good times...remembering this!