The objective of the app is at each level to paint each one of the white / grey / black areas in one of the four provided colours (red, green, blue and orange) in a way that no two rectangles that share a border (totally or partially) will NOT be coloured the same way.
The game play is very addictive but is sometimes hard to touch the correct area on the screen and to set the colour. A global score board connects all results from all players around the world.
Install it from Google Play Store:
https://play.google.com/store/apps/details?id=net.cabecao.C4&rdid=net.cabecao.C4
Project Website:
http://cabecao.net
