Select a weapon from your armoury with your mouse. Click on the direction in which you wish to fire it. Click on the screen when the power reaches your optimum level. You will start the gamewith a budget, indicated under your character. Each weapon will cost you a set amount of money, so you need to balance your budget and make sure you don't and up out of pocket. And out of ammo. Tip Keep your eye out for packages dropping from the sky. These will keep you afloat.