I disagree with removing Underground Jungle - it feels fitting for the environment. It’s not as good a soundtrack as the original jungle, but it’s threatening and mysterious like the Underground Jungle itself is.
I’d honestly get rid of Town Day. It’s just a mediocre, short soundtrack and one you end up listening to for hours on end. It doesn’t have the atmosphere of Town Night and feels too much like it’s just replacing the normal music.
I really hate the ice biome music. The opening is really intrusive and the amount of time spent early game there doesn’t help. It doesn’t fit any other of the cool techno soundtracks of other biomes either. Just high pitched whine in repeat while you are slowed down in the slow stupid water trying to find snow flinx and ice skates. It also doesn’t blend well when traveling through biomes fast and seems to be everywhere despite my best efforts to avoid it, since the underground tundra has no business taking up a fourth of the underground
The jungle night theme. While it is good, there's no reason for it to exist. Other than the forest (because of course), there are no other biomes that have their own night theme. And you find the night theme overwrites the more iconic day jungle theme more often than not.