A puzzle game which contains a visual novel that progresses if you solve puzzles.
This puzzle game is a bit similar to sudoku, but its take is slightly different.
I suggest you check out and understand the tutorial before you solve puzzles. Or at least accompany it with the 1st few 4x4 puzzle to get a grasp on it.
The 4x4 you can do it rather easily, but the 5x5 and 6x6 grids are not so easy and might have several solutions. I dont know if it takes more than 1 solution to consider it solved.
Its not a bad game. You can also write hints just like on sudoku, by using the right click, to help you out.