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* BrokenBase: The third world's dungeon is seen by some as a huge difficulty spike due to the shy guy pots and lots of spark platforms and increased length, while others see it as the easiest dungeon in the game due to the abundance of POW blocks, the near absence of instant death traps, the ease of escaping the Phanto, the fact you get all your hearts early, and the lack of ZergRush enemies in the dungeon.
* DemonicSpiders: Bob-Ombs, when uprooted, often have an extremely short fuse, damaging you if you don't throw them in time.
* DifficultySpike: Depending on whether or not 3-3 is difficult for you or not, this either happens there or in 4-2, a level with a very hard to find fourth mushroom, ZergRush beezos BEFORE you get to the third mushroom, and some annoying platforming involving an autobomb, not to mention fighting Birdo on ice. The difficulty spikes again in 5-3 with an area overflowing with enemies plus a tough climb up inside a tree. Then you have to fight Clawgrip.
* FanonDiscontinuity: To this day, there are fans who still stubbornly refuse to accept the game as a part of the Mario series, never mind the fact that it was originally intended to be a Mario game anyway.
* GameBreaker:
** Peach's hovering ability. Don't have to worry about risky jumps jumping on disappearing logs when you her ability to jump and just levitate over them.
** In general; Luigi breaks vertical jumping, Peach breaks horizontal jumping. (''Mario's'' vertical jump height is actually better than Peach's.)
** Interestingly enough, the game manual declared ''Toad'' this, due to his speed and power, saying that you will use him the most, with Luigi and Peach only for levels that require their jumping abilities.
** The GameBoyAdvance [[VideoGameRemake remake]] made shells rebound from walls instead of disappearing upon contact, and it now ''always'' generates hearts for ''every'' enemy it kills, making it ripe for [[HealThyself exploit]] [[InfiniteOneUps potential]].
** {{Giant|Mook}} Shy Guys and Ninjis, who drop hearts when thrown, making them an easy source of hearts should you find yourself taking too much damage.
* HilariousInHindsight:
** The POW Block and Starman cameos in ''Doki Doki Panic'', which were present before the game was adapted into a ''Mario'' game.
** Luigi being a swap of Mama from ''Doki Doki Panic'' started the whole "Mama Luigi" meme way before people heard it on the cartoon shows.
* ItWasHisSled: The whole game [[spoiler: is a dream being had by Mario.]]
* MemeticMutation: The [[EarWorm overworld music]]. [[http://www.youtube.com/watch?v=Hv6RbEOlqRo IT]] [[http://www.youtube.com/watch?v=MwKclhWlo-0 BEGINS]] (second link contains {{NSFW}} content).
* NeverLiveItDown: Its status as a palette swap of ''Doki Doki Panic'' ensures that ''DDP'' is almost always brought up in media that refers to this.
* ThatOneBoss: Clawgrip. He throws lightning-fast rocks that aren't always guaranteed to slow down enough before going down a pit. Good luck getting past him with Toad or Luigi.
* UnwinnableByInsanity: In World 2-2 where you must dig through sand, it's possible to force yourself into a dead end by digging up every sand block until they're out of your jumping range. Since the game has no timer, you're stuck there. Fortunately, the devs accounted for this; see TheDevTeamThinksOfEverything on the main page. In fact, this scenario provides the trope's page image.
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