These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Accidental Innuendo: Mario rides right behind Peach in the Clear Pipe in the opening cutscene, therefore staring up her dress. The game makes a point of having him, Toad and Luigi look to the side for most of the scene, though.
Awesome Bosses: The battles against Bowser in his car. And especially the final battle against Meowser, the first time Bowser uses powerups to his advantage! The Hisstocrats and Motley Bossblob also qualify.
"Hands-On Hall" is an oddball level based on how people in the west often confuse Japanese and Chinese culture. Not only are its look and sound subtly hilarious, the whole level also has a dungeon-like quality to it that requires you to explore and solve puzzles to progress.
"Mount Must Dash" and the "Honeycomb Starway/Skyway" levels should get special mention for being sendups to other genres: "Mount Must Dash" is a level based on Mario Kart, meanwhile the "Honeycomb Skyway/Starway" levels are based off of top-down shooters. Also, Starway and Skyway use a remix of the Gusty Garden Galaxy theme.
Broken Base: Fans are heavily divided between those who are happy with the revealed game as is and those who are disappointed and wanted a different kind of 3D Mario game. After the game's release, they're divided on whether or not the game deserves all the praise it's gotten, and whether or not it's as good as the Galaxy games.
Captain Obvious Reveal: To anyone who has ever played a Mario game before it should come as no surprise that the boss of World 7 is not the final boss.
Demonic Spiders: Parabones. They replace the normal Dry Bones, but they can fly, chase you down, and revive themselves if they're jumped on or swiped at.
Game Breaker: Peach in a Tanooki Suit due to her floating ability.
It was game-breaking enough that the Statue Leaf in the previous game rendered you invulnerable and able to destroy almost anything by statue-stomping, but here, the Lucky Cat Suit one-ups it with invincibility, so unlike other statue forms in the series, the suit's golden statue form is deadly to the touch, having the same effect as the Starman. The only trade-off being that you cannot move while transformed.
Rosalina herself is a game breaker. Not only is her jumping height on par with Luigi, her spin attack is incredibly useful as both an attack and a second jump in numerous (usually life-saving) situations. Plus, she's able to spin in Super and Small forms, giving her a big advantage over the other characters, who have no form of offense in those forms. It's so useful in fact, it may benefit you more to not pick up power-ups or deliberately take damage if you're already powered up to utilize the spin on occasion.
The touch-screen integration with the Game Pad allows you to break blocks, freeze enemies, and reveal hidden blocks and coins by tapping things on the screen. It also allows you to hit some enemies and potentially defeat a select few without even approaching them. Snow Pokeys can be defeated by tapping their segments, Galoombas get flipped over, and you can even defeat Bullies by tapping them to knock them back. This makes the Prince Bully fights hilariously easy, as all the character needs to do is kick him when compressed, since you can squeeze him into the pipes by tapping him repeatedly. Flipswitch panels can be activated with the touchscreen too, making Switch Scramble Circus and other levels with them incredibly simple. Oh, and bombs can be dragged-and-dropped to where you want them, and detonated remotely by tapping them again.
Once again, the infinite 1-Up easter egg.
Goddamned Bats: The Octoombas, who can only be defeated with a Ground Pound and spit projectiles very frequently. They are also almost always on moving platforms, making killing them frame-perfect.
Not only does Bowser have an amusement park just like Eggman's, it also has all the colors of the rainbow used to make it, and the final boss fights using your powerups against you. All of these are part of the finale of Sonic Colors.
There are levels with dash panels that are reminiscent of some 3D Sonic levels.
Remember the signpost flying away in Crisis City: Act 1 in Sonic Generations? The same thing happens to a Goal Pole in "The Great Goal Pole".
Bowser's final stronghold, The Great Tower of Bowser Land, is an enormous skyscraper decorated with his image in neon lights. In the live action movie, Koopa's headquarters was an enormous (double) skyscraper decorated with his emblem in neon lights.
The golden coin train is often referred to as the hype train.
On /f/, the music for Beep Block Skyway is commonly associated with "pppu~", a NSFW flash animation depicting Peach and Rosalina plus other female characters. NSFW scenes change every three beeps.
Whenever a well-known Let's Player starts playing, expect the Miiverse to be full of messages cheering them on.
Moe: The Sprixie Princesses, especially the green one. From the opening cutscene, where she asks Mario and the others to help her and explains how Bowser's already kidnapped the rest of them, to her eventual rescue, where she happily waves a toy mallet(?) around before opening the pipeline to World 2. Seriously, you'll wanna give her a hug.
Narm Charm: Although Meowser is a formidable threat, his design and name are incredibly silly. The overly dramatic reveal of his fluffy, whiskered face shows that Nintendo was, at least, a little self-aware about it.
Scrappy Mechanic: While it was also a problem in the New Super Mario Bros. games, the added dimension makes the camera an even worse problem in this game when playing with multiple people. It also seems nearly random which player the camera decides to follow.
So Cool Its Awesome: Upon release, the game was very well-received, with reviews praising it as a very fun and imaginative title, saying that Nintendo had proved that the series could go on without feeling samey.
That One Level: Grumblump Inferno, a stage that requires you to run on crystalline blocks that are like Tox Boxes you platform on, that turn on their sides over lava. Some are rectangular, forcing you to cross to the small ends at times. Granted there is a trick to beating it (don't jump, run along it as it turns). But for first timers or multi-players it's an absolute nightmare.
World Crown-Crown (Champion's Road), which definitely lives up to its name.
Any level that solely involves riding on Plessie since he's a little hard to control.
Also, Chainlink Charge, where it is almost impossible to get all 3 stars without falling to your death multiple times.
Cakewalk Flip has red and blue platforms that flip with each jump you take. Not helped by the fact that there is a Ring Burner in the way of getting the 3rd Green Star in this level.
That One Sidequest: The Five Bonus Stamps (the portraits of each playable character, including Rosalina). To unlock them, you have to clear every single level with all five characters. If you're only going for one character (such as Rosalina), then it isn't so bad... but if you plan on going for all five, then the quest becomes a living hell. Especially with Toad.
They Changed It, Now It Sucks: Some players don't take kindly to this seemly replacing the Mario Galaxy style of gameplay and its adventurous/epic atmosphere. And others who prefer the explorational style of 64 and Sunshine aren't happy to see another console game take up the linear style.
Unexpected Character: Rosalina. Even when evidence of her being playable started showing up before her announcement, it still took everyone by surprise.
Win BACK The Crowd: Depending on who you ask, the game itself is an example of this.note Many people legitimately liked the New Super Mario Bros. games when they were released. When it was first announced, a lot of people were not impressed and already wrote it off due to it not being a game in the vein of Super Mario Galaxy or being "Super Mario 3D Land HD". Or New Mario Bros crossed with Mario 3D Land. But when the October 1 trailer went up, it changed a lot of people's minds about the game and restored interest to those who are / were tired of Mario platformers because of the New Super Mario Bros. series. Then the game actually came out and blew folks away with the amount of thought and creativity put into the title along with new visuals and music. It actually feels like a new game rather than a retreadnote Which some felt the New Super Mario Bros. games were with new power ups thrown in. The multiplayer aspect certainly helped as well.
The Woobie: Koopa Troopa. All of the enemies simply chase you around and are stomped by Mario but Koopa Troopa is made a lot more sympathetic. When you jump on them, they slide out of their shell and then they start frantically chasing after it. If they are unfortunate enough, you can steal or destroy their shell which causes them to stop for a second and sink their head down in sorrow. And, then, the little trooper still chases after you, despite his predicament. Avoiding to jump on them would be easier if it weren’t for the fact that you can now ride inside of their shells.