Arc Fatigue: The first several chapters are just Axel and the Professor's journey from Germany to Iceland. They can be skipped without missing anything. These chapters are boring enough in the original, but in the most well-known English translation, they become downright unbearable.
Big-Lipped Alligator Moment: One of the English translations of the book added a dream sequence where Axel (or "Harry", as he is renamed) witnesses a battle between a giant ape and crocodile and is then attacked by the ape before waking up. It's a completely pointless scene that only succeeds in making the reader further lament that the story doesn't feature more prehistoric creatures.
Fridge Logic: Why, in the 2008 movie, is there so much wind in an enclosed underground environment? The vegetation quivers in the breeze constantly, and the first plant encountered is one that evidently relies on wind for seed dispersal.
Special Effects Failure: The 2008 film has special effects that are very often hit and miss.
Tear Jerker: In the 2008 movie, the scene where the characters bury and say goodbye to Max. The entire thing, but especially the journal entry read by Trevor, that Max wrote on Sean's birthday.
