Your goal in this game is to last as long as you can against the enermy armada. Whenever you destroy an enemy you gain score points. You can use these score points in the upgrades menu to upgrade your ship to handle oncoming waves of enemies. Your shield is your primary source of defense. However it requires energy to use it. As you progress through the waves of enemies, the number of enemies you face will increase, there strength, will also increase, and there speed will decrease so they have more time to try and destroy you. Thus is why upgrading your ship is a very important aspect of survial in this game. Every once and a while you will encounter an enemy boss which you must destroy to go on to further waves of enemies. Use either YOUR MOUSE or WASD KEYS to control the game. Good luck!