@titos .... couple of ways. I'm guessing you would like a menu to come up and be highlighted with the game in the back darkened. Do you also want it Paused? If so create a new scene for your menu. Put a full scene actor in the back of that scene and make it black with opacity set to say 40%. Put you other menu items on top of that. In your game put in your menu button (or whatever causes the menu to show) the behavior Pause scene and pick that menu scene in it. You will need to put a button in your menu to resume play and in that button use the unpause behavior. That way the pause scene will open above you game, it will be darkened, and paused. (Play around with the opacity +- 40% to get the right look for you)
Answers
add an actor … centered and screenSize …
(when on scene … make sure it is at top of the top sceneLayer)
interpolate Color.Alpha from 0 to 1
if you just want the bg to show then …
on that Actor … changeAttribute: self.Image To: the background image before the interpolate
you can use instances of this actor for fade Ins/Outs in all your scenes