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.
Most Wonderful Sound: Anything that comes out of Klonoa's mouth. Normally, his Simlish would be the exact opposite, but he's so just darned adorable while shouting, whooping, and "Wahoo!"ing that you can't help but smile when Klonoa does so. (Unless he's hurt or dying in some fashion; that will only make you cringe and strive to prevent it from ever happening again.)
Also that "POOCH-CHI-CHU-chu-ch-ch-ch..." sound that occurs upon harming a boss. Glorious.
That One Boss: Ghadius will be the source of many quick and cheap deaths if you aren't paying attention. The extra health you get in the Wii version does next to nothing to mitigate this.