Infamous is a game where you get to choose to play for the forces of evil or good. Pick your karma at the beginning of the game to determine what your role will be. If you decide to play for good karma, you'll use your X button to find people that are suffering from the attack of the reapers and heal them. If you play for bad karma, you will kill those people without penalty. Use your space bar to use your weapon and attack the reapers (they're wearing the hoods and carrying heavy weaponry). You'll have mini missions throughout the levels to complete and there will never be a dull moment in Infamous.