Feel free to use any of the soundtracks I've uploaded here. Having played your demo I'd recommend this: https://opengameart.org/content/intense-electronic-action-soundtrack

If there's anything you really like the sound of and would like me to expand on, message me on here or email type42production@gmail.com and I could see about creating some tracks specifically for your game if you have a clearer idea what you're looking for.