This is a remake of the old DOS game "Paratrooper".

In the game you play with the gun at the bottom center of the screen. At the top of the screen fly helicopters. They are harmless, but they drop paratroopers. If four paratroopers land at one side of the gun it's game over.
After the first series of helicopters a few planes appear. They drop a bomb aimed at your gun. If it hits you it's game over as well.
This repeats continuously.
To protect yourself you should use your gun to shoot the paratroopers/helicopters and the planes/bomb.
