What would you say is the deal with the super negative reviews? I'm not looking for a 9.5-10 game. I'm looking for maybe a 7-8 not even an 8.5. I wouldn't even rate the original game a 9. Not every game needs to be a 10 it just needs to maintain some kind of standard for its series on genre to me. If it evolves it is some way I get a pleasant surprise, if its what I expect, it should be, that is normal with all products you buy.
I think the deal is that
(1) Many players, reviewers in particular are very presentation-sensitive people. YNI is extremely calm and doesn't scream "I'm awsome" in your face. While the graphics do look great, they are nothing oustanding and lacking in effects, the music is extremely calm and often times just dull. Result: the game presents itself as a bit boring and unexciting, although gameplay mechanics and level design themselves are really great (this category for example is a problem with players like gigglepoo / McShae).
(2) It's the third game using the same gameplay structure, players might just not want to play more of this template and mark the game down for that
(3) In the last few months there have been a lot of 2D platformers, often with newer base mechanics (DKC uses a mechanic from 2010, Rayman Legends is basically new, Puppeteer is new) and always with busier and more polished presentation, this adds to points (1) and (2).
I therefore say, if it's the gameplay and level designs you are looking for, you will have a great time, if points (1) or (2) bother you a lot, you won't.