Anti UFO

Game description
In this game UFO's will appear and kidnap the citizens. If a UFO catches a citizen and leaves the screen, then you lose. As the game progresses the UFO's will move faster and the game will be more difficult.
How to play
1. Use the mouse to control a cannon and click to shoot the UFO's. 2. Sometimes a UFO's will carry items, you can shoot it to get the item to help you protect the citizens.