Sure! I started in FL studio, but I couldn't figure out how to do bulk stuff, so I wrote down all the notes I used and mapped them to midi notes. Then I used the python library midiutil to add the notes I wanted to individual midi files (single notes, success chords, failure chords, and new level / loop chords). Then I made a script to generate oggs for every instrument in the sound font i mentioned (this used fluidsynth + oggenc to map the midi notes to use each of the entries in the sound font) for one of the success chords, listened to them all, picked the one I liked best to be the default sound (hint hint) and then did the same for _all_ the midis (every separate note, success chords, and failure chord).
I think I could have likely just used the sound font directly in the game and generated on the fly, but distributing the sound font itself was subject to their license terms, etc. But just using it to create midi tracks etc. did not have restrictions.
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As for the loop theme: maybe I had a bad interpretation, but you as the player need to loop through all the tiles repeatedly to find a match. And you have to do that some number of times to get to the next level, and you keep doing that in a loop.