MIDI files are “optimised” for Roland SoundCanvas VA/Roland VSC with SC-88 Pro mapping. Your mileage may vary on other soundfonts or romplers.
If the download links are down, please check the “Elsewhere” tab. SoundCloud and Newgrounds also have download capabilities (SoundCloud has the Soundtrack versions and Newgrounds has the looping versions), and I’ve also mirrored the soundtrack on Game Jolt and Itch.
This is the entire soundtrack for Squid Savings, licensed under Creative Commons for your remixing pleasure. MIDIs are also available if you want to poke around, but please don’t judge too hard since I was in a hurry when I made this lol.
To summarise: you may use the music downloads for whatever you want if you provide credit as outlined in the license. If you’re unsure, copy this text:
Music, "SONG NAME" from the Squid Savings OST, by SwiftVector (swiftvector.net), licensed under a Creative Commons Attribution 4.0 International License (https://new.creativecommons.org/licenses/by/4.0/).
This example fulfills the attribution requirements of the license, so if you put this text somewhere sensible (e.g. in the description, in the credits, in a license file) you’re golden.
To summarise the terms of the license: you may use the provided music downloads for whatever you want if you provide credit alongside it e.g. “Medium Security: Hacking In by SwiftVector (swiftvector.net), licensed under a Creative Commons BY 4.0 International License (https://new.creativecommons.org/licenses/by/4.0/).”