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.
Fridge Brilliance: The boss of the Cave Temple stage is a giant praying mantis. Why? Because temples and mantises are both related to martial arts.
Funny Moments: Halfway through the river stage, you find a slingshot and, after much confusion, appear to discard it in favor of an oar for defense. The slingshot comes back up during the final sequence against the giant butterfly.
Let's Go Island's bad ending is actually rather funny, due to the character's bickering over failing the final Press X to Not Die sequence and the fact that they didn't really have much of a relationship going into the game to begin with. It's definitely played more for laughs than the Downer Ending of Ben and Norah's mourning of their broken relationship in the first game's bad ending.
Goddamned Bats: ANYTHING that travels in a swarm, be it bees, fleas, or piranhas. If you miss even one, you'll lose about a third of your health!
Moment Of Awesome: Admit it, using teamwork in order to take down a giant butterfly with a slingshot and a talisman charm is quite something.
That One Boss: The Man-Eating Plant of Stage 3. It's attacks come really fast, and most of the time you'll be fending off multiple Combat Tentacles, each of which you have a very limited time to take care of before they hit for a lot of damage.
And in the sequel, the Final Boss uses a very similar move...