The hero kid who is also an alien is saving the city today. You will have to use Ben 10 and his gun to shoot at those bad guys. The bad guys are attacking both from land as well as air. Aim correctly and take them out. Also dodge their attacks so that Ben 10 may survive. Keep a close eye to Ben 10's life. As more and more enemies shoot at him, it may go down; finally destroying him. Remember to save the grenades as they are limited.
Help Ben 10 Save the city from alien attacks by being the sole hero who is going to fight back. Use grenades when you absolutely have to clear off the difficult mess. You can shoot in all directions, even diagonally.