@weirdami
Well, the biggest part are the musics, and since I've read some points about the huge datapack I will explain why I've made this choice:
1. The game can be very long if played at higher difficulties so to make player could be annoyed by listening only the same tune, personally if I listen too much to a music that I love after some time I start to hate it
I've put much effort composing the soundtrack and that's why I offer the special edition with a separate cd with the OST. There are 12 tracks, 43 minutes of original music, and I hope, good enough for my game.
2. The music and the sound effects aren't compressed and that's why the size is huge, this choice has been made to allow weak or old CPUs to play the game as well streaming the uncompressed audio, the price is bigger file size. I cannot handle a data archive for every platform supported, it's a big task for a single person, it's difficult to handle the source code applying fixes and checks for each platform so that's why all platforms (almost) shares the same huge data archive.
3. The graphics are composed by 65 different backgrounds, a little part are in 800x600 resolution while all the rest are 1024x768, not considering all the sprites used for the options and the buttons.
So, yes, the game could have been OCS and on a single floppy but this is valid for all games around... or it could have been in 16 colors, with a black background and without sounds. But what about the fun?