I'm not sure I ever finished Adventure. I know I never finished the third GB game, the one that is considered no longer canonical. Haven't finished (or even played much of) the MSX version, either.
That being said, I've played a ton of them. I'm really itching for another SotN-styled game, but since Konami seems no longer interested, I have to wait until IGA gets Bloodstained out. It's looking quite good, there's a survey for backers on which shader they prefer, and the character model is really solid.
No, seriously, check it out!
There's also a non-cel-shaded one, but it doesn't look as good in my opinion.