The Paper Mario series has always been a treat, exemplifying some of the funniest writing in any game, numerous tweaks to RPG mechanics, and a skewed worldview that makes me appreciate the Mario universe in a different way.
However, when they stray from their RPG strengths, Paper Mario games lose some of the appeal. For example, Super Paper Mario maintained the copious (copious) dialogue of its forebears, but put aside turn-based battles for awkward platforming.
Paper Mario: Sticker Star isn't as dramatic a departure as Super Paper Mario. It's still a turn-based game, and in fact has some of the most interesting battle mechanics in the genre. It's still delightfully funny and precious. But it's been compromised by the awkward addition of unwelcome elements from adventure games.