Adobe Animate - AS3 Show button?

yes.  here's one way:

var n:int=0;

var btnA:Array=[btn1,btn2,btn3];

for(var i:int=0;i<btnA.length;i++){

btnA.addEventListener(MouseEvent.CLICK,clickF);

}

function clickF(e:MouseEvent):void{

var i:int = btnA.indexOf(e.currentTarget);

n = Math.max(n,n ^ (1 << (i+1)));

if(n==Math.pow(2,btnA.length+1)-2){

// unlock whatever

}

}

here's another:

var n:int=0;

var btnA:Array=[btn1,btn2,btn3];

var clickedA:Array=[]

for(var i:int=0;i<btnA.length;i++){

btnA.addEventListener(MouseEvent.CLICK,clickF);

}

function clickF(e:MouseEvent):void{

var i:int = btnA.indexOf(e.currentTarget);

if(clickedA.indexOf(i)==-1){

clickedA.push(i);

}

if(clickedA.length==btnA.length){

// unlock

}

}