This game is the Defender, well at the beginning there is a start button and after you press that button you can choose a level, there is level 1, level 2, and level 3. After you press the level of the 3 levels you control the tank using w, a, s, d and also space to shoot enemies and you have to protect those behind you and you have to shoot the boss tank and you will win if the tank hits your back you will lose