The combat system is a welcome return to turn-based from the last Paper Mario title on the Wii. The stickers are fun and varied. Where the timing based attack/defense and the roulette systems add depth to the combat system. The best part of the game was the combat by far.
That said, the levels are frustratingly designed to say the least. The copy that was sent to me had a save that stopped at Yoshi Sphinx which is pretty early in the game (2-2 I believe).
In that level there is a hidden door that I spent over an hour trying to find which triggers an easy boss fight. After that you have to backtrack back to the beginning and finish the level. I now know why the previous person sent the game back.
I cleared the rest of world 2 until 2-5. You had to find a large sticker that you don't see in any of the levels you just played. A walkthrough mentioned that 3 stickers are hidden in the previous levels that make up the one large sticker and I was supposed to find ahead of time but, were never hinted at in the game. I turned it off and put it back in the mail after reading that.
Artificially extending the game with lame backtracking should have been a thing of the past years ago.
Be prepared to have a walkthrough near by as there is almost no story and no direction in the game.