First of all, I would assert that there is no such thing as a "videogame music style" and I think that you're relying on repetition for a lot of your thematic development because it's the simplest method of progressing. My suggestion is to let go of what you think a "videogame music style" is supposed to be like and try metabolizing something a bit more linear. As they say, you are what you eat, so start eating something new--listen to different kinds of music and try to write in different composer's styles.
Don't be afraid to edit the tempo track--not everything has to be at the same tempo. Try writing full orchestral gestures. You could think of this as stingers, but something that has shifting moods. Try writing a piece that starts out sad but turns happy and does not loop.
Check out the following piece by master composer (and living person with most Oscars), Alan Menken for the underscore to Beauty and the Beast:
Count how many thematic and emotional shifts there are, how does he move between them?
Notice how the orchestra will move between acting as a single instrument and a more homophonic lead and accompaniment style.
How many different textures does he move through?
Get your head out of JRPGs for a while and soak up a new vegetable. You're stuck in a rut because you listen to the same stuff over and over again.
Good luck and feel free to contact me if you want an exercise or an assignment.
