That's right, you should use ROM that hasn't been trimmed, or used by any flashcart before...Any game that you download and unzip is a clean dump.....
Well, you will have some soundtracks in the game, but few of them are deleted, and sound effects like when characters call each other when you switch them, or sound of your jump..stuff like that...I can't remember very well, it's been some time since I played it..
It''s not that big of deal, and it's really worth it to play a game!!