Gradius
There are plenty of other changes that had to be made to accommodate for memory limitations of a cartridge in 1986 though.
Famicom
Makai Mura
A better choice would really be to just turn down the volume and listen to something else, instead of this tinny and interrupted rendition of an originally good soundtrack
Dragon Quest
Despite all of the genuine care that went into trying to make Dragon Quest successful in the US, it just did not sell as a $50 game. There were so many unsold copies that Nintendo eventually gave it away free with new $20 subscriptions to Nintendo power, further sweetening the deal with a strategy guide that contained a full walk-through and additional back story.
Hokuto no Ken
Of course all of the game’s mechanics were detailed in the manual, but if you don’t have it (or access to the Internet, if you’re playing this in modern times) then you will probably never make it past the first stage.
Dragon Ball: Daimaou Fukkatsu
Akira Toriyama himself actually played this game with his wife over the course of two days. He commented in an issue of Weekly Shounen Jump that “It was pretty rough dying immediately from a game over, but it was faithful to my source material and I was very excited about the differences. They weren’t all that far removed from it, and I really liked Konpei”.