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.
YMMV: Zack & Wiki: Quest for Barbaros' Treasure
Best Boss Ever: The Giant Squid battle. A long, drawn out battle of wits complete with a stormy backdrop, torpedoes, unprecedented teamwork, and firing a giant ship's mast not once but twice!
Ear Worm: Bonelich and his catchy remakes of old Capcom songs will become this to you!
Fridge Brilliance: The locks on treasure chests look like Wiki's head, because Wiki originally cursed Barbaros.
Scrappy Mechanic: Bonelich's music minigames and the sword duels in the penultimate stage are often targeted as this, resulting from the way the game expects the player to find out how to properly control something with only a position picture for reference and people being unable to figure out how to do so.
Surprise Difficulty: Despite the light and graphics, the latter puzzles are incredibly hard even for skilled gamers.
That One Level: Mad Science. There are several ways to mess up the level and make it unwinnable and it takes a while to find out how to even progress through the level.
Viewer Gender Confusion: Wiki's a girl... maybe? It doesn't help that after the final battle Wiki's voice talking to Zack sounds like a young woman. The character entry on Wiki uses "he" though.