It's a Mario game. It's pretty obvious what to expect.
I'd still play it, though. It's good to jump into the time machine and head back to 1992 every now and then.
However, I have to say something to people who take Yahtzee's reviews as the main deciding factor in your purchases: How stupid are you? Yes, Yahtzee's a critic/QA man/reviewer/whatever he wants to call himself in a review on a given week, and yes, the reviews are as informative about what the game will entail as they are funny. However, his taste in games and (I assume) yours may not be one in the same. True, games like Psychonauts and Saints Row 2 are awesome, but maybe there are games Yahtzee's reviewed that you may like and he was more or less (hard to tell, sometimes) negavite toward. Example, Yahtzee seemed pretty negative toward Brewtahl Brutal Legend, but I loved it. By contrast, he seemed to enjoy Painkiller, while I found it sort of underwhelming. Point is, there are things that people agree on and things people don't. Even if Yahtzee says something's good or bad, that doesn't nessecarily mean that it will be to you. This is why I take reviews with a grain of salt, using it more or less as a jumping-off point of what to expect and not subject to the game's quality or my possible liking of it instead of taking the whole review and interpreting it as, "Yahtzee's words are the only truth, ergo it will be the sole deciding factor in a game purchase." Don't take the review at face value and completely ignore a game just because one person doesn't like it. I get it, though, you don't want to blow money on a bad game. That's why video stores and Gamefly exist. How do you know if Silent Hill 2 was the epitome of atmosphere in a game? Maybe Super Mario Galaxy 2 wasn't a glorified expansion pack. Try it for yourself and find out.