NightRaid is a battle between you and the enemy forces.  
You managed to get stuck in an anti-aircraft bunker in a strategic area, without any troop reinforcements.  You know that the enemy is going to be coming in droves, so you're glad that you have a huge supply of ammo to defend yourself.  They're ugly.  They're stupid. They're weak.  They're so unfriendly that they can't even get along with each other.  Unfortunately, there are a lot of them, and they're all out to get you!  The enemy aircraft will be coming across the top of the screen, dropping paratroopers as they go.  You need to prevent the paratroopers from landing, because if three of them land, they'll be able to invade your bunker and overpower you!  
You can shoot the planes.  You can shoot the paratroopers.  You can shoot the paratroopers' chutes off, and watch them plummet helplessly to the ground (killing any paratroopers that happen to be underneath).  Basically, if it moves, shoot it! 
Now, go get 'em! 
