The Music from suraimu that never saw the light of day. old boss music, different credits music, music for customised seeds, and music for more worlds. The game was originally going to be 100 waves long, so half of the music isn't used and either in the files or only in archived versions. As a person who modded the game before becoming an official developer, I have found lots of secrets in the code. Remember back when there were cheat codes? The answer was 3451 and it allowed you to kill everything in one hit. Before the red moon and the mountain, there was "Agressive Aftermath" a vector background with fireballs on the floor. Did you know that the slimes used to appear from a cave on the right side of the screen? Probably not. Anyways, this is a lot of text and I'm bored typing so bye.
@graveheart for Suraimu, the only scratch project I know how to help code. These are just 5 music tracks, if I forgot some I will add them later.