Nintendo put a lot of work into Paper Mario (Very slight gameplay spoilers)
Finished world 3 and 4 right now, and despite it feeling cumbersome having to go back and forth between levels in world 3 for a side-ish main quest, worlds 2, 3, and 4 had levels that were just... very ingenious. I felt like I was playing Super Mario 64, just with Paper Mario gameplay sans the full RPG-ness. That mansion in world 4 where you go Boo hunting... dat Yoshi Sphinx. There were just a lot of levels in this game where I felt the amount of thoughts put into it. The amount of time it takes to beat each level speaks for itself. The things related puzzles were intuitive, though occasionally a bit too vague. Just on the creative levels and such alone, this game deserves a solid 8 or higher. But why not any higher than 8? Why potentially lower?
Boss battles are too exciting, and it makes you keep wanting more, but not particularly because there should be more. There seems to be mini-bosses everywhere, which is good. The end of the world bosses are far more intensely challenging where the game succeeds very well in making you feel like you're in a very well designed RPG boss battle. However, it's easy to make these bosses good. You don't have levels, so difficulty doesn't change depending on how much a person grinds. So that's just it: these boss battles are fixed difficulty, thus a fixed way of defeating them. This is why YOU SHOULD NEVER LOOK UP A FAQS TO BEAT THIS GAME! Once you figure out from the vague hints this game gives out which thing sticker you need to use to make the bosses not borderline impossible (or literally impossible), it's just downright satisfying. Some of these bosses are possible to beat without the use of these thing stickers. However, beating them without it feels drawn out, and your sticker inventory will end up looking devastated. However, it is still equally satisfying. It's just a shame that the lack of proper RPG elements downgrade the genius of the builds of these bosses.
Dialogue is just top notch. Whoever wrote the script for this game deserves a goddamn f***ing medal.
Here are why this game may turn you off though: smaller battles are annoying and useless for the first 3 worlds. There are too many goddamn enemies in certain parts (that f***ing river in one of the world 3 levels). If small battles are not really that helpful in the earlier parts, they should have put a little less of it. Meanwhile, it's starting to become helpful to get those easy small battles that require a sticker that's easy to get to OHKO all the enemies. Those give tons of coins, and occasionally they give rare stickers.
There are no traditional RPG elements. After you clear World 3, you are rewarded for your curiosity should you go back to World 3 and look around. This is where the whole "Oh your HP increases over time, so it's a full RPG" argument kinda falls apart. I'll leave you to figure out why. Stickers do see a noticeable gradual enhancement, and the previously fearsome foes are... no wait, they're still annoying. Either way you need to spend a sticker to defeat them, so you don't particularly feel much stronger going back to the previous enemies. You do, but you still feel the need to run away and save your stickers instead.
Sometimes, hints are TOO vague. I've heard a lot of complaints about this from professional reviewers. Never ever forget that L button brings out Kersti who will give you hints. Many times I've forgotten. Until the Boo Mansion of World 4, I had not realized how damn helpful she can be.
Partners are nonexistent, and Kersti is too unlikeable. This game attempts to remedy that with charming NPCs that reoccur. They do a decent job, and the characters you have to interact with the most end up feeling like your partners. You even end up liking one of the end of the world bosses. It's a shame the boss isn't reoccurring prior to the battle.
I give it 8/10