Hi Karen.
Nice to see (read

  you back! I played it the way you do, I said FREEZE and then let the students turn around. I just didn't have to pay close attention to their peeping or not since I let the other group see a flashcard. 
The rubber ball sounds silly I know. However, it is a very successful tool in getting each and every student to say something during class. For some reason which I can't explain (i have never been a fan of ball games) students seem to enjoy catching the ball and saying whatever they are supposed to practise saying. I have a collection of small balls, one looking like a hedgehog, one a funny little smiling face (five cms in diameter), another one that opens up and becomes 5 times its original size when you throw it.  I find  that the moment you 
ask a question and throw the ball an electic current goes through the class and everybody is eager to take a turn.  With my 8-10 year olds I do this at the beginning of each class to revise things we have learnt to say so far.eg. "Where do you live?" . The first student answers and throws the ball to a student of his choice and repeats the question.  When I think they have had enough practice with that I clap my hands and I get the ball back and start a new question thread.
The rubber ball can very well be replaced by a a crumpled  piece of paper.
Happy teaching.
Manuela