If you expect a follow up to Paper Mario: The Thousand Year Door, then you'll be severely disappointed.
If you expect another spin off game like Super Paper Mario, then you'll be okay with it.
If you expect a Paper Mario game that is almost entirely Adventure oriented, then you'll love this game.
There are no RPG elements, other than turn based combat. Your character does not progress besides increasing health similar to any Zelda game.
The puzzles are excellent, and it has an oldschool adventure feel to it, where you can become completely stumped by a particular puzzle or enemy, and need to think outside the box (or at least think like the designers.)
An excellent Mario game as long as you don't consider it a Paper Mario, or Mario RPG.
The game should be called: "Paper Mario's Sticker Star Adventure"