Factual error: Roaming the Istanbul marketplace in the prologue, the protagonist Antoinette Marceau mentions that the rugs look as if they might be able to fly "like the fabled Aladdin carpet." The association between Aladdin and the magic carpet comes from the Disney movie, it's not something a lady in the 1930s would have said.
Character mistake: During matches involving Triple H, one of the random tidbits Jerry "The King" Lawler can mention is the match Hunter had on Wrestlemania 2000, where he bested in a fatal four-way "Mick Foley, the Rock and Mankind." Mick Foley IS Mankind, the fourth person in the main event was The Big Show.
Character mistake: When Fatman begins to explain the 'party' rules, he says "If you prefer to stay in ONCE piece..." This is a spelling error, as he should have said 'ONE piece'.
Audio problem: "Message In A Bottle" has a guitar outro with extra vocals that is not in the master track.
Bug: Return Of The King, Level 4: The Battle Of Pelennor Fields - The orc army is approaching Minas Tirith at the start of the level clip. But as the "camera" pans around, half of the orcs literally disappear.
Factual error: When giving birth in the game, giraffes will lie down, as do other in-game animals. Giraffes in the real world rarely lie down and even give birth standing up.
Revealing mistake: If you take damage and lose a wing or both, the Arwing's shadow still shows two wings.
Continuity mistake: There are some minor inconsistencies between the original game and this prequel regarding Chloe's time at Blackwell Academy. In the original game, Chloe's dialog during episode three suggests she's never been in principal Wells' office, but in this prequel, Chloe is seen visiting the office. Additionally, this game, which is set in 2010, shows Chloe being expelled. But documentation in the original game indicated she was expelled in 2011.
Other mistake: Starting a new game, the description for the Fiction mode says... well, exactly that. "This is the description for the Fiction mode." Nothing else at all. Placeholder text at the very beginning of the game.
Continuity mistake: In the ending cutscene of the G5-Building level, you will see you have come out of a plain wall, which you blew down before completing this level.
Other mistake: In the opening sequence, Dr. Wily's name is misspelled Dr. Willy with two L's. This mistake is carried over to Mega Man Legacy Collection 2.
Factual error: In 'Escaping the Prison', the description for the Opacitator says that it will turn you opaque, allowing you to pass through walls. 2 problems. First, opaque is the opposite of transparent (see through), despite what the description claims. Also, the transparency of objects only affect how much light passes through them, it doesn't affect any other physics (a glass can't go through walls just because it is transparent). Even if the device did make objects opaque, it would not affect any physics or have any effect on Henry.
Audio problem: If it is raining, like in the Halloween event or other random storms in the game's time cycle, the audio can change in structures you're inside. But the rain follows the rules as well, like if you're in a tunnel, the rain doesn't fall inside the tunnel. However, if you get inside a bus that is in that tunnel, suddenly you'll hear the sound of rain hitting the roof of the bus, despite there not being any rain that can hit it.
Audio problem: Several lines in this game are said where the character's mouth is out of sync for at least a third of the line. Especially Doc's lines.
Other mistake: Keith's stun glove is misspelled as "stun globe" in the inventory screen.
Plot hole: Level Five: After finishing the mission to defeat The Dirty Bubble atop the Sea Needle, the game completes, the Dirty Bubble is stopped and Bikini Bottom is saved from the little dirty bubbles infecting them. After saving the day, the game lets you go back to Bikini Bottom to finish off some other missions, but despite this the citizens are still infected by the little dirty bubbles and if you go back to the Sea Needle, the Dirty Bubble is still waiting there and reading to be battled again.
Bug: If an NPC zombie is too close to certain obstacles, they will appear to be crouched on the ground. The Collision is just enough to cause them to not be able to make any sideways movement unless they are activated, thus they will just be crouched on the ground slowly rotating around. It is comical for a group of zombies to be doing this while occupying the same space, as they have a dog pile effect making a tower of crouched rotating zombies.