Okay, I've managed to find it, it was totally my bad. I've used some 24-bit wav sounds, but it happens that SDL_mixer plays those on some systems and does not on other.
Here's the updated archive for you: https://www.dropbox.com/s/phmsd9mv51t1hk2/darkness-looming.tar.gz?dl=1
Oh, and if there'll be no sound, please try running it with the environment variable SDL_AUDIODRIVER=alsa.
Sorry for all the fuss :)