Thanks for playing :) The music bug in the end sequence is known, but since it wasn't game breaking, I didn't bother to fix it (yet). The other bug sounds interesting, never heard or saw that happening. If I find the time to work on the content update again, I will look at this as well!
If you want to replicate the bug, jump through the middle platform, then fall through it, then jump through the right platform and fall through it etc. until you enter the whole code. Then just jump up through some random platforms and you'll get to the top. This bug actually really confused me when I tried to guess the code using the "wrong platform" sound. I once entered a part of what I thought was the code, then thought I made a mistake and fell to the bottom, and then I didn't understand why the code "changed" and why it went back to normal (I went through the wrong platform).
Also, I think I came up with an idea on how to fix this. I'm guessing you have an if statement checking if you're going through a platform and your vertical speed is positive. You could turn that into an if-else statement, with the "else" part removing the last entry in the array of the platforms you've chosen, decreasing the number of platforms entered correctly(just make sure that doesn't go below zero) by one or "undoing" going through a platform in some other way (I don't know what you're using for entering the code).