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.
Good Bad Bug: By collecting any secret weapon, you can use the secret weapon of all characters by simply switching character in mid-charge while still holding the button. This means you can delay collecting Gil's bombs until just before you head to the dark area, but makes low percent completion slightly more painful, as by utilizing this trick the bombs are the only Secret Weapon you MUST collect. See Sequence Breaking below for why this can get painful.
Nausea Fuel: You see those white ropes that dangle from floating platforms and that you use all the time? They're the platforms' drool (or possibly mucus)... Yuck!