Being the only good review so far, maybe my opinion is biased by childhood nostalgia, but I am definitively not exaggerating when I say this is one of my favourite games ever for the DS. Although the (initial) plot is near identical to its predecessor, the actual gameplay feels more polished and capable of delivering a solid experience. The core mechanics of exploring and gathering food to survive are mostly the same, in a good familiar way. You'll still probably explore alone to go faster rather than bringing your companion, but at least now you can cook for yourself! (which in my opinion is one of the most entertaining aspects of the game, given the many possibilities to choose from as you unlock more methods, gather recipes and find more diverse food)

The option to choose your character at the start of the game may be seen as a good upgrade, but in practice it falls kind of flat since the male character can climb faster (VERY useful) whereas the female character can only jump further (only useful to get a couple of extra materials in the jungle iirc). But that is the only "bad" aspect I find this sequel to have.

The rest of the game delivers a fresh-but-familiar setting in brand-new areas whose maps feel way more rich, diverse and lively. The way all the areas connect with each other is less linear in structure, more spacially rational and way better done in general (have I mentioned yet exploring is my favorite aspect of this game?). Although they feel fun to live in once you've gotten used to your surroundings, it is true that at first they may appear confusing and dreadful as you are forced to explore them with a starving character struggling to survive... but that's part of the charm! I think young me wouldn't have become so obsessed with this game if it didn't have this sort of mystique and dread that comes with being unfamiliar with your bearings in a desperate condition (where you may have died several times as well). Being able to adapt and learn how to move forward and how to make your characters live one day longer becomes such an integral part of the experience, that when you finally know what ticks and what doesn't it feels so rewarding to be able to survive comfortably in these surroundings, and you start seeing them as the home they now are for you. Exploring every nook and cranny until the point of knowing them like the palm of your hand never felt so enjoyable.

Although carving your little way of living life getting by in this island of yours may very well be a goal in and of itself, it's understandable some may have in mind your return to society as soon as possible as the main goal. In that regard, the possibilities for escape felt quite sound and satisfying.
The ending of its predecessor felt like it took out the charm of being in a deserted island and I didn't fancy the pseudo genre change in how you had to operate and everything to proceed, but this game does exactly what a deserted island survival game should strive to have as its endings, they feel natural and what you'd expect to do in such a situation.