A bit late, but I'm open to ideas with explanation. Don't count on everything getting in though. An entire fan-made expansion to this already fan project, the Extended Tale of Diep exists and less than a dozen of its conceptions have been added.
While the current stand-in BGM (despite him actually having his own battle theme in the final game) being from something called Elsword, he will receive his own amazing BGM that will be an even greater spectacle in good time.
Oh. Well thanks for letting me know. When the game is complete, please send me the link to the site if it's a browser game, and if it's a download send me the download link. Please put it on my messase wall.