You don't need to do that for each star.
Basically, when you have some repetitive task to do in programming, you have to tell yourself that there HAVE to be a way to avoid copy/pasting.
Because after all... Good programmers are lazy programmers :D
The way to avoid that is loops
basically do a foreach on your stars and look at the corresponding value in the Array
System: On start of layout
System: foreach Star
Array: Value at(Star.ID) = 1
-> Star: Set opacity to 20
FirefoxIcon(wtf?): On collision with Star
-> Star: Set opacity to 20
-> Array: Set value at(Star.ID) to 1
And why do you need two dimensionnal Array? Value at (X,Y) you only need a Value at(X). If its value = 0 your star isn't picked, if it's 1 it is.