Desceiption / How to play:

ApoHitori4k is a type of logic puzzle
published by Nikoli.

There are 3 simple rules:
1: no two circled squares with matching
   digits may exist in the same row or column.
2: no two dark color squares may be directly 
   adjacent to one another (touching corners doesn't count).
3: no circled square or group thereof may be completely
   isolated from the rest by shaded squares (again, touching
   corners doesn't count).

FAQ:

Q: Hey I like that game!
A: Thanks.

Q: Do you make more ingenious 4k games?
A: Yes! Try them out and visit my 4k game site.

About the game:

ApoHitori4k was made by Dirk Aporius,
for the 2013 Java 4k Competition.
The entire game is less than 4kb.


Source code