add optional circle cell
NumberLink 2000+ is a simple yet addictive puzzle game, once you play, you can not stop.
Simple to play:
just try to connect the circles of the same color,and fill the whole board.
Be careful, line can not cross over each other.
hard to master:
Think hard to resolve all the levels.Try to complete with least moves.
features:
1. over 2000 levels for all kinds of players, from kids to master
2. 12 different borad sizes, from 5*5 to 16*16
3. rate star for each level
4. hint for each step
5. solution for each level
