Great game for being on the Game Boy. This Zelda is a little different but a lot awesome.
First of all it doesn't take place in the usual Hyrule. Second, the namesake of the game doesn't appear in the game at all (even though Marin looks like Zelda). There are a ton of Mario characters in the game Tarin looks like Mario, there is a Luigi look-alike on Tal-Tal Mountain. Princess peach has a cameo in a photograph and there are Mario enemies galore in this fourth title in the Zelda series. Shy-Guys, Piranha plants, Goombah's and a lot more Mario enemies crawl about dungeons.
They added in some side scrolling to hearken back to Zelda II along with some platforming elements using the Roc's Feather to help you jump around.
Collecting the instruments was a fresh thing to do, a lot better than the usual crystals or tri-force pieces.
All in all, this game is really different but in a really great way. I especially liked how they added in some cut-scenes, something that you really didn't even see in Zelda: A Link to the Past.
BEST MOMENT: Getting the ultimate weapon in the game. The Boomerang?!! Yeah, strongest weapon in the game and I think that's awesome!
WORST MOMENT: The Final boss was a little too easy. Usually I wouldn't complain about that but he was a lot easier than some of the mini-bosses that I fought earlier in the game. It was just like, meh... ok.
FINAL JUDGEMENT: This is definitely one of the best games in the 2-D world of Zelda. I like this one a lot better than A Link to the Past. It just flowed better and had some pleasant cut-scenes. It is just a really great game and I fully recommend it.