When asked by the BBC what the next big Sudoku-like craze will be, puzzle guru Maki Kaji (whose business card reads "Father of Sudoku") points to Slitherlink. The grid-based logic puzzle has all the ingredients of another hit -- easy to learn, straightforward gameplay, and simple rules. Even though it doesn't have the broad appeal of Sudoku, Kaji says it could easily earn the title "son of Sudoku".
In Slitherlink you stare at a grid made up of dots and the numbers 0, 1, 2, and 3 scattered about. Your goal is to join the dots around the numbers using the same number of lines as the number they are next to. The line snakes around the grid like ... a snake. Hudson published Puzzle Series Vol. 5: Slitherlink in Japan earlier this year and the game has received high marks from reviewers, including a 10/10 from Eurogamer.
It isn't known if Slitherlink DS will make its way out of Japan, but thanks to the world wide web and the humans that populate it, a Slitherlink-inspired game has been crafted in Flash, cleverly titled Slither Link.