DKM Hanidoku is a variant of Sudoku where you need to place numbers in a grid. The major difference is that the grid is in the shape of a honeycomb rather than a square and instead of having nine rows, columns and blocks, it has nine rows, incline and decline lines.
As with Sudoku, each row/incline/decline must have unique numbers but not all lines are nine cells in length. Those that are less can only contain consecutive numbers. For example, a line of length seven must contain the digits (1,2,3,4,5,6,7) or (2,3,4,5,6,7,8) or (3,4,5,6,7,8,9) in any order.
All puzzles start with a few cells already filled in to get you going and are solvable by pure logic alone - no guessing required.
There are three new puzzles each day, one at each difficulty level.
Try the tutorials first to familiarize youself with this type of puzzle and some of the strategies used to solve them.