I have started another basic game. It is based loosely on Defender but here you pilot a Colonial Viper trying to save humans from the Cylons.
The humans are trying to escape using underground turbo trains. There is a map at the top of the screen consisting of a number of boxes that indicates the different sectors of interest along the track. The sectors with trains are represented by a filled in box while an empty box indicates a sector with no train. A Cylon head on the map indicates a group of Cylons are chasing and monitoring the train. Your location is represented on the map by a flashing cursor. The map and ship controls (ESDX) are working but not much else at the moment.
Eventually the game will allow you to shoot the Cylons and collect the people in the train. After you have collected the people they will need to be delivered to safety to score points. If you encounter any Cylons and they shoot you down then the people and any potential points would be lost. If you do not save the people on the trains then the Cylons will eventually get them and then move onto another sector with a train.