I read many reviews of this game, and they're all over the place. The most consistent criticism is that it's not as clever or as innovative as the 1995 original and that somehow makes it a disappointment. Now, I'm no stranger with disappointment from this series considering how mediocre Yoshi's Story was, and how way off the mark Yoshi's Island DS was, so I understand there's a solid history of games in this series being let downs. That being said, I played through the first world of Yoshi's New Island, and I have to say that it's a lot of fun. The reviews are completely right that it's not as clever or innovative as its 19-year old progenitor, but I'd argue that it doesn't have to be in order to still be fun. A large chunk of this game's target audience wasn't even born when that game came out, and for them this may be their first experience with the series, and I think it's a good one.
The key to enjoying the game, like many Nintendo games with aesthetics aimed at children, is to grasp that these games are consistently designed for two levels of experience.
One: Being able to finish the game and see the credits. Like with the Kirby series, this is intentionally designed to be easy so that young children can feel a sense of accomplishment. Seeing professional game reviewers with decades of game playing experience piss and moan about how it's not challenging enough to do this makes me roll my eyes, especially considering Nintendo just gave them two super challenging platformers in the last year with New Super Luigi U and Donkey Kong Country Tropical Freeze.
Two: Being able to complete the game with all of the collectibles. This is where the rewarding gameplay, challenge, and clever level design come from. This is what seasoned players with lots of platforming experience under their belt should be playing this game for. Trying to get all of the red coins, stars, and flowers on each stage is challenging and rewarding, and playing with this goal in mind makes the game much more interesting.
Again, I had a lot of fun playing Yoshi's New Island yesterday. It might not be the sheer genius that the original Yoshi's Island was, but it's a fun game, and I like it.