You will be a small tank and you will have to defeat your enemies. Shoot them before they shoot you, because if they touch you first, youll have to wait till your tank will be repaired.
Try to defeat your enemies and dont forget to catch all gold coins you find on your way because you will need them to buy items for your tank (arms, ammo,...) and build vigilance towers.
And if you feel you have an innovative day, you can build your own maps and play there.
It needs Microsoft DirectX 9 or higher