A very simple error I made om my EnemyShip class was placing a } bracket in the wrong area. It gave me the error message: "ActionScript 2.0 class scripts may only define class or interface constructs."
I made a similar mistake with my Ship class and got the error: "This statement is not permitted in a class definition." This also made my ship unable to be moved by my keyboard.
So if you got either of those errors check to make sure your } brackets are in the correct spaces. Otherwise the program has been very simple to use so far, onto #5!
 "Shootorial #4"){kind=icon}