The Bad : The game can be insultingly easy with unsubtle "hints" being thrown at you at every turn; and if that wasn't bad enough, the "emotion"-driven gameplay is blatantly sexist. Minimal replay value. Bizarre, incomprehensible story.
Princess Peach... all the guys want her and all the girls want to be her... well... not really, but the game was certainly a lot of fun while it lasted. Without straying too far from the Super Mario formula, it's part SMB and part Yoshi's Island in its presentation and level design. The levels are also no where near as linear as the traditional SMB games, and SPP adopts a cute art style which brings in an element of femininity uncommon to the SMB series.
The game is relatively easy for more experienced players, so those seeking more a challenge can give this game a miss, however the experience in and of itself is enjoyable enough to justify a rental at the least.
The most unique element of SPP is its emotion-driven gameplay, which, while sexist, allows Peach to harness powers based on over-the-top displays of emotion (and these are joy, anger, sadness and happiness); however, these emotions can only be harnessed as long as Peach has "vibes" in her vibe-meter. Don't let the jargon throw you off; it's actually quite straight-forward in the context of the game, and the game is hardly challenging with your little talking umbrella guiding you through every facet of the game.
Super Princess Peach is recommendable for the more casual gamer, however, those seeking a fun side-scroller in the spirit of the Mario series will also find plenty of like about Super Princess Peach despite its arguably superficial flaws.