4 months late probably counts as a necro, but I only just realized that my HIB4 had the soundtracks and got them myself :P. I wasn't satisfied with the answers present and after much research, I think I've nailed down the information not completely covered in other answers so this should help those who are sticklers like me.
Cave Story essentially has 3 sound tracks - Original, Remastered and New. All three are selectable to be used during gameplay from the options menu in Cave Story+ or at least they are in my steam install.
The "new" soundtrack for Cave Story is a rearrangement by Yann van der Cruyssen for Wii. The Cave Story+ sound track included with HIB4 is a 44 track selection from this "new" sound track. This sound track is also included in Cave Story+ (Steam) in (
Program Files (x86)\Steam\steamapps\common\cave story+\data\base\Ogg) +/- a few songs which I'll cover in the answer.
The "original" Cave Story Soundtrack has 42 tracks listed + 2 added for +/Wii. The site also lists 5 unreleased, but I'll address the added ones in the answer and the unreleased in the extra information. The source of the track titles listed and the order come primarily from the fan-translation of the original game release and have been accepted within the fanbase. The translations are mostly pretty spot on. Most of the tracks in the "original" sound track are part of the other sound tracks. These files can be found in Cave Story+ (Steam) in (
Program Files (x86)\Steam\steamapps\common\cave story+\data\base\Org) in Pixel's proprietary .org format.
There is also the "remastered" sound track that was present in Cave Story 3D on the 3DS. It is a rearrangement by Danny Baronowsky with feature arrangements by K-Wix. It includes the same titles as the "original" sound track (including Wind Fortress) with 2 extra remixes. These files can be found in Cave Story+ (Steam) in (
Program Files (x86)\Steam\steamapps\common\cave story+\data\base\Ogg11) split into an intro and a loop. I'll address these in the extra information.
Here is the matchup of everything file-per-file derived using Sebastian Wolff's site which uses the order from Cave Story Music, the steam files and some gameplay for confirmation:
# HIBST Filename Steam Filename Accepted Song Title
1 access.mp3 access.ogg Access
2 vivi.mp3 vivi.ogg Gestation
3 mura.mp3 mura.ogg Mimiga Town
4 plant.mp3 plant.ogg Plant
5 ginsuke.mp3 ginsuke.ogg Balrog's Theme
6 gravity.mp3 gravity.ogg Gravity
7 cemetary.mp3 cemetery.ogg Cemetery
8 anzen.mp3 anzen.ogg Safety
9 wanpaku.mp3 wanpaku.ogg Mischievous Robot
10 kodou.mp3 kodou.ogg Pulse
11 weed.mp3 weed.ogg On to Grasstown
12 fireeye.mp3 fireye.ogg Eyes of Flame
13 mdown2.mp3 mdown2.ogg Meltdown 2
14 dr.mp3 dr.ogg Tyrant
15 escape.mp3 escape.ogg Run!
16 jenka1.mp3 Jenka.ogg Jenka 1
17 jenka2.mp3 jenka2.ogg Jenka 2
18 maze.mp3 maze.ogg Labyrinth Fight
19 grand.mp3 grand.ogg Geothermal
20 ironh.mp3 ironh.ogg Oppression
21 marine.mp3 marine.ogg Living Waterway
22 quiet.mp3 quiet.ogg Quiet
23 wanpak2.mp3 wanpak2.ogg Scorching Back
24 oside.mp3 oside.ogg Moonsong
25 requiem.mp3 requiem.ogg Hero's End
26 plantation.mp3 curly.ogg Cave Story
27 lastcave.mp3 lastcave.ogg Last Cave
28 balcony.mp3 balcony.ogg Balcony
29 lastbtl.mp3 lastbtl.ogg Charge
30 zonbie.mp3 zonbie.ogg Zombie
31 lastbtl3.mp3 lastbt3.ogg Last Battle
32 bdown.mp3 bdown.ogg Break Down
33 hell.mp3 hell.ogg Running Hell
34 ballos.mp3 ballos.ogg Seal Chamber
35 ending.mp3 ending.ogg The Way Back Home
36 fanfale1.mp3 fanfale1.ogg Got Item!
37 fanfale2.mp3 fanfale2.ogg Get Heart Tank!
38 fanfale3.mp3 fanfale3.ogg Victory!
39 gameover.mp3 gameover.ogg Game Over
40 toroko.mp3 toroko.ogg Toroko's Theme
41 - white.ogg White
-- - - XXXX
42 credit wii.mp3 - -
43 ika.mp3 ika.ogg -
00 intro menu.mp3 - -
?? jenka1b.mp3 - -
X - kaze_intro.ogg Wind Fortress
Y - kaze_loop.ogg Wind Fortress
- 40 of them match straight across
- The track XXXX is just a 21 second track of silence so you can ignore that.
- I don't think an extra album for 4 tracks that were included together with the rest is the correct solution. One approach to bonus tracks is to append them all to the end, but I prefer a case by case approach. I think intros are good to open a soundtrack with and that credits music makes sense at the end, followed by other bonus tracks, but it's up to your discretion for these 4.
- credit wii.mp3 is credit music so why not call it Wii Credits and list it at the end as would be done with credits? From what I've been told, this track was rearranged, but was never actually used even on the Wii version. It is a bonus track as part of the "new" sound track.
- ika.mp3 is a musical reference to ika-chan so call it Squid and put it wherever you please, but since it is a bonus track exclusive to the "new" sound track, you could just put it after the credits as that is where bonus tracks are usually placed. Apparently this gets played on the title screen on Pixel's birthday.
- intro menu.mp3 is supposedly the music from the intro menu so I'd just call it Intro Menu and place it first as the intro is the first thing of the game that you hear, but it is a bonus track exclusive to the "new soundtrack", but it seems it was never used so you could put it there or somewhere at the end of the disc. The music actually used in all versions use the given sound track version's track titled Cave Story. On the Wii dashboard, it is not used either as it appears that a clip of tumult's re-arrange of Cave Story from the Cave Story Remix Project (Disc 2) is used.
- jenka1b.mp3 is an alternate arrangemet of Jenka 1. I'd call it Jenka 1 Alternate or Jenka 1b. I'd personally put it after Jenka 1, but as it is a bonus track exclusive to the "new" sound track and was not used so tacking it on at the end wouldn't be wrong either.
- White is actually part of the "new" sound track and plays in my copy of the game, but was not included with the HIB sound track. White may have been omitted from the Wii release even though the track was rearranged so this may explain its omission. The file is in your game files in .ogg format and you can convert/add it if you wish a complete "new" sound track.
- kaze_intro.ogg and kaze_loop.ogg are not technically part of the "new" sound track as they are the same files copied over from the "remastered" sound track, but when you play Wind Fortress, as those files are with the "new" soundtrack files, it should play the "remastered" version of Wind Fortress, but I haven't unlocked Wind Fortress yet and cannot confirm.
I'm not sure how much of this applies to the HIB install, but this is what I've found with my Steam install.
- Wind Fortress and Halloween 2 are present in the game files for the "original" sound track (
Program Files (x86)\Steam\steamapps\common\cave story+\data\base\Org) and can be grabbed from the Cave Story music web site. These should play when you have "original" music selected, Wind Fortress will play in the Wind Fortress and Halloween 2 under special conditions. They are a part of the "original" sound track, but were not included in the many earlier releases because Wind Fortress wasn't included and I guess Pixel wanted some cool omake so Halloween 2 may play on Halloween in place of another track (*needs confirmation, but I believe I read this somewhere. Sort of like how on Christmas, all sprites are replaced, I also saw Halloween replacement sprites in the game files so this would make sense).
- The unreleased tracks on the Cave Story music web site are from an old music server sort of deal and were acquired with a bunch of beta tracks. See the beta music page for the full story. You may want to grab them too for good measure and maybe place them as part of a separate Cave Story Unreleased album if it suits you.
Program Files (x86)\Steam\steamapps\common\cave story+\data\base\Ogg11 contains 101 files. Every song in this folder is broken into an intro and a loop except for lastbtl, meaning that there are 51 tracks here, but since silence is just that, the 3 fanfale tracks are the same as the 3 fanfare tracks, balcony and balcony2 are the same, credits and ending are the same, and bdown and breakdown are the same, there are actually 44 tracks. This is the "remastered" sound track which is a rearrangement by Danny Baronowsky with feature arrangements by K-Wix and found on Cave Story 3D. The tracks need to be combined if you want to really add them to your music collection. I have done so personally, but as they are part of a commercial distribution rather than the free release of the original game, I don not believe I am at liberty to share them. Notably, the new tracks added here are the remastered kaze (Wind Fortress), lastcave2 (Last Cave 2) (either this or lastcave in this sound track was remastered by K-Wix and the other by Danny Baronowsky), and wanpaku ending (Mischievous Ending?) which appears to be a mystery as to who did it or if it is ever used in-game. I don't know how to swap the Last Cave music used in-game aside from file renaming, but there may yet be an in-game way as only one of them is used.
EDIT: Added more information per a discussion on the Cave Story tribute site forums.