No idea what to do...

I have projects that I am working on and that, however I am stumped on what I should be learning at the moment.

I feel fairly comfortable with the language at the moment, I don’t know every part of the Java API but when I discover something, I figure out how to use it fairly quickly.

So I am not sure what I want to learn at the moment, I have been using LibGDX for a year now but feel as if I can’t do much that is impressive.

Like I want to learn how to do shadows, lighting and all that but not sure where to begin. Like for instance in Ray’s Sixty Gig he has a cool blood particle effect, things like that.

Not sure what I should be learning…I was also considering completely revising Physics and brush up on fundamental Mathematics but trying to get the time to study that stuff is not as easy as learning something in terms of coding.

What direction should I be heading here, completely lost.