*** UPDATE ***
As you may notice, the GBA soundtrack mix mods are now smaller in memory size (58.9MB to 21.9MB).
This is because I made the .OGG files of the GBA soundtrack mix smaller by removing some of the music parts that are unused in the game and by compressing the soundtrack with Audacity.
You might think that it reduces the music quality, but it's actually not noticeable. Trust me.
I also fixed some of my translation errors (stupid me).