Tune Den: The Fall
The music is a mixture of eeriness and mechanical/electronic sounds, which fits well with the game’s setting of an abandoned planet populated with robots. My very favorite track though is the first one you hear, Planetfall.
I am also fond of the two combat themes that you hear throughout the game. They are certainly on the energetic side.
And it’s impossible to resist the creepily cheery Domesticon theme. It will forever remind me of rotted human heads.
If you’d like to hear the entire soundtrack, I’ve put together a YouTube playlist for it. The only thing that I have to complain about is that it’s so short (approximately 30 minutes long).