When I first saw golden sun it was near the start just before you go on the epic quest, when I first played it was a phenomenon the areas that you visited were amazingly created, the characters brilliantly made with the development and design, the djin have got to be one of the cleaver game mechanics of the time.
The sounds for its time were phenomenal on the gba, yes you probably could have made the characters look 3D or even provide voices on the game cube or PC but Nintendo just proves to everyone with this game (and lost age)  graphics don't make the game, the game play does,

As for addictiveness from the moment I first saw the game running (funny enough on my brothers gba sat on a counter while he was doing something) I was wanting to play it see what it was like and what it was about, when I did get to play it that was amazing just going from one area to another being told a story and collecting djin, even the mini games were fun the amount of times I ended up just buying herbs and other items just to get raffle tickets was unbelievable. 
The story.. Well for me it is like a game version of Harry potter, when I first read HP I didn't want to put the book down until I finished.

Difficulty its hard in parts but if you level up right then you can easily beat the game (it does have some parts that require a bit of thinking but it is fun  

Seems ok but reviews need about 550-600 words per avrage so this one is kinds short but good try.