Paratrooper

You are a brave solder defending a gun which should prevent the landing of enemy airborne forces.
The concept of the game is extremely simple - you control the gun located in the center of the screen. The shoot targets are: helicopters, paratroopers, planes and bombs. The constant bombardment of your bunker additionally complicates the task.
The game ends by a nuclear explosion in one of the following cases:
1. A paratrooper has landed on the gun
2. At least four paratroopers have landed on the right or on the left of the gun
3. A bomb has hit the gun
Gun control: touch the screen, and the gun will aim and shoot at this point.
Features:
- The more shells are in the air, the more expensive becomes each new shot of the gun
- The explosion of a helicopter can blow up another one flying in the opposite direction, and always kills the paratroopers in the explosion zone
- The plane can be destroyed by a gun shot only
- If you could reach 500 points, wait for the bombers and try to grow your score up to 600 points
- If you have already got 1000 points - the game becomes incredible hard...

Shooting points:
- Helicopter: 3
- Paratrooper : 2
- Bomber: 5
- Bomb: 15

The game is written based on the old and well known game "Diversant".