The object is to fill the grid with numbers or X's so that all the numbers form one big cluster - connected either vertically or horizontally.
No two adjacent numbers can be identical.
Each number indicates how many adjacent numbers are next to it.
Grid sizes go from 6x6 to 15x15.
I've done about 10 levels at the 6x6 & 7x7 levels. It is obvious to me that this game is a Labor of Love for Guenther. He's taken his time to get everything right. Everything.
If you're still playing Sudoku, take a break and try this game.