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.
Game Breaker: Arty Wario's upgrade gives him the ability to draw health refillers.
Goddamned Boss: Stuffy the 64th. Fall back a room and he refills his health. Get caught by Cannoli and you have to do the whole fight over.
That One Boss: The second form of Terrormisu. You have to use Cosmic Wario to hit a selection of three heads that pop out of holes in the wall. The catch is you have to hit all of them in one shot.
The Woobie: The Lurchin enemies. As it says in the Monster Compendium: "This emotionally fragile urchin hurts everyone he touches, no matter how hard he tries not to. He spends each night sobbing from nearly unbearable loneliness."