You need to figure out how to get the electricity to make a line with all of the appliances in each level. As you complete each level they will increase in difficulty. The wood disappears when you click it so keep that in mind. It will also help you to think of the cause and then the effects of your actions. That thought process will allow you to complete each level with minimal difficulty. This is very addicting and will make you think. See how far you can get.