Use WASD or Arrow Keys to move, Mouse to aim and left click to shoot.Key "1" will switch the gun to Pistol and key "2" will switch the gun to Machine Gun.Press the "P" key to open shop.As the waves increase the zombies start moving faster.A boss zombie spawns at Wave:5 which drops 100 cash when killed.You only have 3 lives so play carefully!!!
Thanks to @warfame for the youtube tutorial on "How to make a Shooter Game in Scratch"