The classic Mario action is just that, and I like it. Not much to say there.

The puzzle component comes in as you gain special abilities over the course of the game. Much of the gameplay involves figuring out what combination of abilities are necessary to get past various obstacles. I like these kind of puzzles because you generally know ahead of time exactly what all your options are, and the trick is to figure out what set of options will accomplish your goal. In contrast, many adventure games (Myst, Lucas Arts adventures, etc.) involve puzzles where the challenge is in figuring out what you are allowed to do in the first place, which sucks, because it involves a lot of random searching and clicking with no rational thought. Paper Mario generally avoided that, thankfully. However, the puzzles were generally not very complex; usually getting past any particular obstacle required using just one ability, with quite a few abilities available by the end of the game. I much preferred The Lost Vikings' approach, where there were only a couple abilities, but you usually had to combine several of them to negotiate any particular area. Still, I found it fun.

Finally there was the RPG component. Super Paper Mario involved a story line and dialog. The story line itself was not bad for a Mario game (though certainly not FF-caliber). But the dialog... well, the dialog sucked. And the reason it sucked was because there was way too much of it. I mean, I like a deep, detailed RPG storyline with lots of dialog (Xenogears), but if you're going to have a mostly shallow, light-hearted story with intentionally cheezy dialog, for the love of God, keep it short! Much of the dialog in Super Paper Mario was not only trite, but tended to repeat the same general ideas over and over again. Of course, I feel like I have to read it all because sometimes there are important tidbits in there.

Also as part of the RPG component, instead of the classic small/big/firepower life system of side-scrolling Mario games, you have HP and items. For the most part I felt this added nothing to the game except complication. I never felt any desire to use any of my offensive items, because it seemed like it defeated the purpose of playing the game: I wan to beat the guys through agility and jumping on their heads, not by choosing an item from a menu! So, instead, I only ever used curative items. But that's a problem in itself: assuming you keep stocked with healing items, there is basically no way you could ever die, because you just use one of these items whenever your HP gets a little low. I did not die once, or even come close to it. Kind of disappointing, really.

Aside from the gameplay, the art style was quite interesting. Instead of using realistic art, many actions are animated as if the characters were actually two-dimensional. For example, when Mario turns around, he actually flips like a card, briefly appearing flat. When Mario goes down a pipe, he is divided into many small squares which get sucked down in waves. It's all very interesting and pretty. It's neat to see game developers realize that making things intentionally unrealistic can be a good thing. It's also nice to see people still making 2D side-scrolling games in today's world of powerful 3D hardware.

Overall, worth playing. Not the most amazing game ever, but fun.