Eu não tenho certeza se está totalmente correto(manjadores retrô tem mais conhecimento sobre isso):
"In case anyone is curious about the differences for all of the games:
-CV1: Very minor visual differences, the Japanese cartridge version added an easy mode and some minor balance changes.
-CV2: This is weird because... the Japanese collection has the NES version, not the FDS version, so we might not get this one either. The biggest difference is a changed soundtrack, though some people actually prefer the NES one.
-CV3: The big one. The NES version got a bunch of updated graphics (including some fixes to both visuals and glitches) but got the music stripped down a lot. A Second Quest got added, as well as a bunch of cheat codes. However, the difficulty was also significantly ramped up in the international version. Grant was much more useful (his default attack was essentially a free dagger subweapon and he could use it while climbing; the international version gives him a short melee attack and you had to find the dagger and use hearts to throw it), heart costs were increased or added, dying to Dracula meant doing the whole level over instead of starting outside his boss room; and the damage system was changed. It's a huge amount of changes, just read all this.
-CV4: The only major differences are more crucifixes and blood in the JP version. Apparently the whip sound is different?
-Kid Dracula: This... is already basically the Japanese version, unless we're getting an old unreleased official release that had gameplay changes we didn't know about.
-The Adventure: I can't find any record of differences.
-Belmont's Revenge: JP gets Cross, US gets Axe.
-Bloodlines: The NA/JP versions are mostly identical outside of Eric's design being more masculine in NA, it was the PAL version that got hit by a lot of blood censorship. The JP version is easier, though."