Right, three people wanted an elaboration of the first review, so here we go.
During the review, there was one small paragraph with gripes, of which there were 3 in total:
Firstly, they lamented that Yoshi apparently doesn't appear as frequently as they wanted him to.
Secondly, they thought a couple of extra characters instead of a second Toad "would have been nice".
Thirdly, they did indeed put in a comment about no online capabilities; I guess this one is not that trivial. Bear in mind that the reviewer himself claimed that "these were minor qualms and weren't a detriment to the game overall".
I suppose I've been prepared for no online mode since Nintendo dismissed the questions about it way back in June, so this didn't seem like that big of a deal. I can understand that it's more significant for people with nobody near them who would want to play a 2D Mario title. ONMUK assure us that it plays really well by yourself and everything can be achieved with one player's efforts, which is what was most important to me.