Me and my friends used to play a lot, we were about 13 or 14. We didn’t have a proper board so used an upturned tray and had handwritten paper for the number, letters, yes, no and exit.
All had a great fun and laugh until the last time we did it.
We were in my bedroom there were 4 of us playing. As soon as we started it was different than it usually was. The glass was moving so fast none of us could keep out fingers on it. We all got scared pretty quickly and kept asking “it” to exit, it kept going to the NO and after about the 10th time of asking it flew off the board through the exit area.
We all breathed a sigh of relief. Then one friend laid back on the bed and seemed to be unconscious, we were trying to wake her up and then her torso started lifting off the bed in an unnatural fashion, like she was being lifted by her belly button. After around a minute (felt a lot longer at the time) she came to and started crying, but didn’t remember anything.
We all walked her home and me and one other friend walked back to our homes (we lived close together), when we got to my friends house we discovered that her watch had stopped at 8.45pm and it was actually around 10pm by this time. We called our other friend and hers had also stopped at 8.45pm. We were all pretty spooked. When I got home my bedroom clock had also froze at 8.45pm.
The next day we went to check on our poorly friend to see if she was okay and she seemed fine, we carried on with hanging out listening to music etc. I then said I wish I could give up smoking and the poorly friend said “I will ask The Man if you can” me and other fiends all had a WTF look on our faces and then I asked her what she meant, what man? All she would say is a dark man in a hat and she wouldn’t say any more. We never did it again after that and never spoke of it.
I didn’t sleep in my bedroom for a year after that. A good few years later we redecorated and when we took the wallpaper off the walls, there was a picture of a man in hat scribed into the plaster of the wall. 
I would never mess about with them again and would strongly advise others not to either.