Now it works (In the online-version here under "run game")
But I stopped playing, since I was only testing, so I returned to the comment-section (which did not pause the game) and now the soundtrack doesnt stop :/
Constructive critic:
One thing that I always find annonying (I am a music producer and sounddesigner) in similar game concepts but also in point and click-adventures: Once you have music playing in a scene, it is quite shocking if the music stops abrupt if I enter another scene. The music of scene1 schould shortly fade out, while the new scene2 is building up / appearing. A crossfade is maybe non-trivial to produce, but a simple fade-out of 2-3 seconds should be possible and if you combine that with a delay of 1 second before oyu place the music-start at the following scene, you should automatically have a smooth crossfade...
Something like in Shards Of God, which is a point´n´click, but features scene-swapping as well ...
Shards of God by Honza Vávra, PacoDiago (itch.io)