You don't need to have a hundreds place in your decimal (but if you want to have a Version 0.1.2 I'm won't be stopping you).

I like the fading of the closing windows. This looks like the type of scenario that the classes are meant to be reusable, but as of now you have all these windows and a button but you're the only person with access to the classes (I can only get the .jar file with the actual .class files not the .java files).

If I have a certain gadget equipped, and I then get out even though the gadget is still equipped, it doesn't say so on top. It just says "Equipped:" with no picture afterwards (unless I go to the store, then come back). I ate about 60 fish, but on the score board it only says 17.

Is the button an Actor? If it is then you can just do getBackground().drawImage and draw the button onto the World's background. (I guess it's a matter of opinion, but I don't think that the blue circle is very decorative.)

If you're only using the blue circle to play sound, then the coding for playing the sound can just be in the world class. All this scenario does is plays sound with a background picture showing, so you just need one class with code in it which plays sound.