While I am not sure if this is actually a fix, going to the Another Otter Folder (sometimes located in C:\Program Files (x86)\Steam\steamapps\common) opening the options.ini file in text editor, changing AlternateSyncMethod=0, to instead AlternateSyncMethod=1, and SleepMargin=0 to 1 instead, and then changing your refresh rate on your monitor in your windows or linux settings to 60, the framerate will now be locked to 60. The slow version runs at 45 fps, where as the fast version is 60, so this is the only solution i could find. Many may argue that this is tampering with game files, and "Cheating" but there is no way else. I would like anyone who uses this to mention it in the description, so Mods could choose whether they think it is cheating. I would like to mention that changing the music is allowed, so i would like this to be too.

I will take a deeper look into that in the next few days with the help of @JanWegh. However i am pretty sure that the game still runs on 60fps for the ones who have the slower version. And are you sure that it is 45fps? How did you come up with that number? Mathematically it should rather be something like 55fps, since you are able to complete the first level faster in 2.07 and slower in about 2.26? seconds.

Sadly i dont have a device that runs the slower versions myself, so i cant do much research at the moment.

Edit: Oh and btw, i see no problem in changing the music files, and once we find out what the other settings are these files.

I use steams fps feature in their overlay to see it, and yeah my slow version fluctuates from 40 to 48 usually, look