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.
Breather Level: There's one that's very clearly intended to be as such by those who designed it. It's the final bonus level unlocked by getting all the fireflies in all the other levels. A lot of players are likely to expect the hardest shit ever, especially if the level is unlocked after obtaining the game's hardest-to-reach fireflies. However, what they get instead is a very simple, open-spaced layout with easy-to-reach fireflies and two paths of fireflies with pre-placed objects leading right toward the end at the final stretch. It's quite easy to obtain all the stage's fireflies in the minimum possible runs (two) without even really trying.