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: Wario World
Anticlimax Boss: In all non-Japanese versions of the game, the Black Jewel only has one phase, and this phase can easily be exploited by outrunning the fire laser attack; unless it traps you in the fire, it won't use any of its other attacks, which results in a very bland and repetitive final battle.
That One Puzzle: One of the underground puzzle rooms from Pecan Sands, which involves punching arrow blocks in certain directions in a certain order to get to the diamond. It is very difficult to solve out without a guide or prior knowledge.