Puzzle by Nikoli W Masyu (Windows)

You won't use any letters or numbers in this original puzzle - the only hints are black circles and white circles. "Masyu" is a puzzle in which you draw a line through the spaces according to the rules. Learn the attributes of the black and white circles and you'll be able to play in no time. The patterns through which lines can be drawn are more numerous than you can imagine, and discovering tactical moves is also fun.