There is amazing world of Slitherlink you never tire of, made with simple rules and four numbers 0, 1, 2 and 3.
Nikoli Puzzle Guide [Slitherlink] (Text Version)
| Akari |
Fillomino |
Hashiwokakero |
Heyawake |
Hitori |
Kakuro |
Kurodoko |
LITS |
Masyu |
Nansuke |
Numberlink |
Nurikabe |
Ripple Effect |
Shikaku |
Slitherlink |
Sudoku |
Suraromu |
Tentai Show |
Yajilin |