I've figured out how to animate the main menu. Basically it uses the method as animating the actors which is frame by frame. I find this feature a bit tedious as one animation have to be done frame by frame unlike the timeline based feature that flash has.

As now I'm only making Bawang Putih swing, it's alright, but I can't imagine how I'm going to animate other objects in the main menu if they are to move too. And Stencyl only gives you 2 layers, foreground and background. Foreground can be animated separately but in the same way as Background.

Anyway, here is how I animated Bawang Putih on the swing :