In Science world you get to choose from one of famous scientists to play as. Once you have made your selection press the button at the bottom of the screen to begin the game. Next you can select the world you want to play in. Each world is different so be sure to choose wisely when you are making your decision. The goal of the game is to see how long you can keep your world alive. In order to do this you have to pay attention to your character. Make sure to really watch their happiness while playing the game.