You are the last line of defense standing between enemy and the only bridge that connects two sides of river and holding it is crucial for your victory. All you have to do is to fire at enemies approaching the bridge with your cannon and destroy them before they reach the bridge. Also some enemies like tanks and airplane will fire at you, instead of coming toward the bridge. So you must destroy them as fast as possible or otherwise they will destroy you. The enemies come in waves and you will lose if your health bar reaches zero. But you have some power ups that can help in your fight. The repair ability is available from the start and can heal half of your health bar. There are 3 other power ups and 3 upgrade levels for your cannon that can be purchased using the coins that you earn by destroying enemies. Each time that you lose, you are redirected to upgrade screen and can improve yourself to fight better next time!