how do i turn off the music
also it crashes every time i kill the nightmare heart
The HTML5 version is now updated to include a sound adjustment menu. For the Desktop versions the update will come with the next expansion, which will add content beyond the Nightmare Heart and should be out by the end of the next week. You should however be able to play and encounter new enemies (++ variants) after the Nightmare Heart. I am unable to reproduce a crash at the Nightmare Heart; which platform are you using?