In this game, you play as a soldier who is sent to a city that has been overrun by aliens. Your objective is to survive as long as possible while fighting off waves of aliens that come from the right side of the screen. You use guns and other weapons to defeat the aliens and can collect power-ups and upgrades along the way to help you progress further. The game also features a variety of different enemy types with unique attack patterns, as well as boss battles and other challenges that add to the gameplay experience. As with the previous games, you have a limited number of lives to complete the game, so you must use strategy and skill to survive.