to drummerman58--assuming you are asking a true question and not just complaining about the set up. 3 stars = nobody touches the gems at all; 2 stars = a gem gets touched (even a little bit), but it is not removed from the screen; 1 star = one or more gems gets removed from the screen, but you keep at least one. All of the boards are set up the same way, so no matter how hard the board is, getting 1, 2 or 3 stars is the same method.
You can try putting it right next to the ice tower and setting it for "close" it doesn't help all the time, but it does cut down on targeting other balloons.
i wish we could move the towers as long they have not popped any balloons. That would help me with the "Crap, I put it in the wrong place," I sometimes immediately get, but not mess with the need to really think through placement.
The extra slot for medals is for completing the track on reverse mode. It doesn't matter what level you complete it on--there is just the one medal. I wish there was a slot for each level so you could see which ones you had done. (I'm too old to remember!)
ycz6--did you go to the big question at the bottom where it says Generate random level? That held me up for a while. It doesn't mean in the forty levels, you have to do a different one.