In Diamond, Pearl, and Platinum.
Oh, the worst slot machine game ever? No wonder I didn't know: I never sat there and completed 15 straight games (I realise that Clefairy points at which slot you're supposed to stop, and the moon being red is bad..)
Speaking of game corner games: anybody have any tips for the Voltorb game? I can and have gone up to level 3, but it seems that I just get super lucky when that has happened.