Nice free game
The game is mildly challenging but enjoyable. It requires enough brain power to be a good workout for the brain. The hardest part for me was how to play the game.
On the bottom of screen are 5 "buttons". These represent the difficulty of play. 1 being the easiest and 5 being the hardest. You don't actually touch the number but the squares around it. 3 means three squares are lit and 2 means two squares are lit. The challenge is not to have 4 sq lit if the # is 2. Just play around with the game and the logic of the game will come to you.
It's a great game for warming up your brain, especially if you have to wait for that first cup of caffeine.