Super Mario Kart/YMMV

Base-Breaking Character: Some say he is a good character, but it seems everyone either loves or hates Koopa. Toad also counts, to a certain extent.
Character Tiers
Game Breaker:
- The Feather often allows racers to jump over walls for huge shortcuts in a game where traditional shortcuts are rare and minimal. Because of this, the TAS abuses it to no end.
- The heavy characters (Bowser and Donkey Kong jr.), despite their low acceleration, have the highest top speeds in the game. For expert players, Bowser and DK are easily the best choices for tearing through courses at top speed-- provided they don't hit anything. The inverse is true for the lighter characters-- they have better acceleration, but their top speeds aren't as high as the heavyweights.
Goddamned Bats: Plenty of obstacles, but particularly the Monty Moles that malevolently jump out of their holes just in time to hit your kart, stop your momentum entirely, and slow you down until you press R enough.
Nausea Fuel: Motion sickness from all the driving, moving backgrounds, crazy colors of Rainbow Road.
Nightmare Fuel: The game over theme has scared some players who experienced it. The Ghost Valley tracks can also have elements of this because the racers are driving on wooden courses that are the only solid ground they can find and the barriers break on contact. The rest is a dark void surrounded by Boos in the background.
Scrappy Mechanic: The fact that the game is always in split-screen, even in single-player mode, where the map takes up half the screen.
That One Level:
- Rainbow Road due to the total lack of guardrails between you and the Bottomless Pit, exceedingly narrow track, and special Thwomps that can wipe you out at the mere touch.
- Donut Plains 3 also fits this trope because of the double hairpin and the narrow--and broken--bridges.