To easily get the Xbox Live Achievement of "Hexic Addict" or "Complete 100 games of Hexic" go to Time mode and start a game under the normal difficulty setting. You must get at least one cluster for the clock to start. Do so, and wait for the time (50 seconds) to run out. This counts as a full game. You can do this as many times as needed to get the "Hexic Addict" achievement.