i changed some music and backgrounds, for example music of snes, i dont like start with zelda musc (for example) i feel it too noisy... so this is my custom list:
PC Engine CD
Game & Watch
Sega Megadrive x32
brother if you like some one change, take it, be free, i will upload a video soon (may be this week), i do not know how to take screenshots of that, may be i need a HDMI recorder case? how do you do? also the sound part is very very important in this case.