This is a missile defence type game where you shoot down aircraft that are trying to drop A-Bombs on your city.

In the titlescreen press option 1 for easy 99 pts or option 2 for hard 999 pts.
If you get to 99/999 pts there is a small ending sequence.
Every 20 pts there is a level up, and the bombers will fly faster.
In hard mode your city´s shield will be fully restored every 200 pts.