In this game you must destroy the aliens, birds and flagship as you go through five screens of nasties.
In order to help you, you have a barrier and also, on all but the first screen, multiple firing.
To destroy the birds, you must get a direct hit on their legs. On the final screen, the alien inside the flagship must be shot in order to clear the sheet.
If you manage to clear all five screens, you will go back to screen one - but this time there will be more aliens swooping more frequently.
Game Controls
Z - Left, X - Right, SHIFT - Fire, RETURN - Barrier