While not as good as other Paper Marios, this one does have a way of ahem "sticking" to you.
As Paper Mario goes, this one has a pretty weak story especially when compared to Thousand Year Door and Super. It's the Mushroom Kingdom Sticker festival celebrating the arrival of the Sticker Comet when Bowser shows up and steals the power of a Royal Crown Sticker that makes him all shiny. He grabs Peach, leaving the festival in ruins. And that's it. Mario of course has to go to the rescue but yeah, no fun new characters to meet, except for a lovably simple Wiggler, no side story with Peach or Bowser and what they were doing while Mario was running around. You're only new friend is Kersti, a bossy silvery crown sticker who will go down in the annuals as one of the worst Mario characters ever. Fi was more useful than her. So yeah where Paper Mario was known for mixing up the tired "Bowser kidnaps Peach formula" this one almost reverts back to the first Paper Mario taking place in the good old Mushroom Kingdom with the usual grass, desert, forest, ice, etc. levels. Though it still tries to have that self-referenial sense of humor.
So this is how the combat works now. It is back to turn based but instead of having a menu of attacks, you collect stickers scattered throughout the levels and purchase in shops then select them in battle. So your book will be full of jump shoes and hammers. Also scattered throughout the land are "things" which are random items like fans, staplers, cats, that can be converted into stickers and these work as suped up attacks, though many times I found myself hoarding these things for boss fights. They also have special functions elsewhere in levels to open new paths or clear out roadblocks giving this more of a Zelda or Metroid feel of gameplay. The nice thing is, once an item is found, you can repurchase it at a store in town as opposed to hunting around for it again.
Kersti's one useful thing she does is "Paperizing" where she lifts you off the page and this is used to place stickers and scraps in places in order to progress.
So since battles no longer increase HP or attack power, why not bypass them, well as you find out later, battling gets you coins and in many cases stickers which you do need. At first having only a couple album pages limits you but towards the end you'll have more pages then coins to buy stickers to fill them. To fill more attack slots Kersti will let you spin for 3 coins to increase your attacks per turn and like with other Paper Marios, learning to time attacks and blocks is crucial to success.
I kept going back and forth on this game. For a while I stopped playing it altogether getting annoyed at Kersti waiting until half way through a boss fight to tell me that if I had "this" item I could beat it easily. Hunting around for additional exits and being forced to fight enemies with no purpose. But I went back and gave it another chance and found myself getting into it. It's not a horrible game especially if you judge it on its own merits instead of trying to compare it to the rest of the Mario RPGs. And I found myself addicted to filling up the sticker museum.
Much like NSMB2, it's perfectly servicable, plays well and can be fun if you let it and don't expect too much but I really hope the next Paper Mario installment steps it up a bit.