If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Its very interesting logic game. You need cross the rivers, but a terrific thing is you need to travel with devil. Help the boys and devils to cross the river. Click on them to move. Then click the GO button to move the boat to opposite direction. If the boys are out numbered by the devils on either side of the river they get killed by the devils.