This game originated in Japan.
The rules are really simple so you could enjoy hours of challenges, from easy to complex difficulty.
Fill in some of the empty cells with the following rules:
1. The number in a circle indicates the total number of continuous black cells extending from it, vertically and horizontally.
2. Dragon circles may have any number of black cells around them.
3. Cells with circles cannot be colored.
This game includes:
+ 350 challenges across 7 levels of difficulty.
+ 7 new daily challenges (1 per level of difficulty)
+ Autosave of your progress solving a grid so you could pause and resume as you wish.
+ No time limits to complete a challenge
+ 2 global leaderboards
+ Full Tutorial
+ and many more capabilities