Air defense - Flak those aircrafts down!

Defend your base from bad aircrafts trying to take you down! In this game, you control some flak cannons and you use them to take down various enemy planes coming in waves against you.
When you start you have only two cannons, one based on your control tower(the left one on the screenshot) and one ground-based, next to your tower. Taking down enemy planes gives you money so you can buy more units to increase fire-power and upgrades with many effects, like radios for better shot accuracy and repair units to recover damage.
As the game progress, enemy planes are faster and harder to kill, so you have to manage your money the right way if you want to stay alive! When you shoot, your artillery fire explode on the air, making a black cloud. The enemy planes take damage only when pass through that cloud, so keep this in mind when you target at them..
That's it, here is the link if you want to try it yourself: Air Defence 3