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.
YMMV: Super Mario 3D Land
8.8: Gamespot slapped it with a meager 8.0, while other outlets such as IGN, Game Informer and GamePro gave it higher scores. While other reviews had arguably legitimate reasons for lowering the score in the game being unoriginal or being overly easy for much of the game, Gamespot's written justification? "[Super Mario 3D Land has] limited StreetPass and gyrometer features." In the words of the site's very own user-created magazine System Wars Monthly:
This is true, Super Mario 3D Land only has limited use of motion control and StreetPass, which is very disappointing. Much to blame is the game's genre, a platformer. Seriously, how are you going to use StreetPass and motion controls on a handheld platformer? This is clearly a big mistake on Nintendo's part.
Game Breaker: Once you get your hands on a Statue Leaf, you possess the power to destroy most of the game's seemingly indestructible obstacles by letting them collide into you after transforming. Spiked balls? Gone. Spiked rollers? Scrap metal. Banzai Bills? They explode, leaving you unscathed. You can even go on the offensive with this by jumping over your obstacle in question then transforming.
Because every single level is meant to be able to be cleared with small Mario, the Tanooki Leaf in general is a massive Game Breaker because of its hovering allowing the player to skip enormous amounts of the more difficult platforming segments. The Fire Flower and Boomerang Flower are more useful for collecting certain Star Coins, but almost every level is made drastically easier with the Tanooki Leaf.
Internet Backdraft: Not towards the developers or reviewers, but towards PETA, who attacked the game on the grounds that the Tanooki Suit promotes wearing fur. (They even made a parody flash game, Mario Kills Tanooki.) After realizing how much of a hornet's nest they stirred, they tried to claim a "Just Joking" Justification, but not everyone's buying it.
Brentalfloss put it best in his "RANTAlfloss" about MKT, after showing how Mario gets his suit in 3D Land, and then asking PETA if they saw Mario skinning a raccoon alive.
Scrappy Mechanic: Nintendo has been pretty good with recent Mario games on setting aside special areas you can repeatedly visit just for power-ups to help with replayability... Except this game. Once you unpack an item from any of the Toad Houses and leave, it's gone for good. Nothing will bring the houses back except getting a Game Over, and you'll be hard pressed to encounter one with the plethora of 1-Ups the game gives you. You can also nab power-ups from stages, but if you want to leave the stage with the power-ups in question, you have to complete the level, as exiting the course does not save your progress.
You can replenish the Toad Houses through StreetPass tags, but if you don't live in a big city, that may be easier said than done.
Cosmic Mario chasing after you if this is the first Mario game in a long time (basically forces you to keep moving). Then there's the stages where you have 30 seconds to start and you have to find ways (usually stomping on Goombas) to get more time. Now try stages with both!