Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Revealing mistake: The shot of Hobgoblin tossing pumpkin bombs at the ceiling inside Landon's lab is a recycled shot from the previous episode when he tossed bombs at the ceiling inside the auditorium. (00:12:05)
Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Continuity mistake: When Beast is holding Wolverine above the vat of chemicals, the way they are gripping hands alternates between Wolverine gripping Beast's closed fist and their thumbs overlapping each others' knuckles. (00:11:00)
Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Revealing mistake: The same two guards are repeatedly shown trying to stop Wolverine and Spider-Man inside Landon's complex, despite the fact that Wolverine and Spider-Man are repeatedly shown dispatching them/knocking them out in other rooms within the complex. (00:05:20 - 00:08:15)
Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Revealing mistake: The same shot of two guards running towards Spider-Man and Wolverine is used three times. (00:05:20 - 00:08:10)
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Revealing mistake: The same footage of Beast swinging through the trees while trying to catch up to Spider-Man is used twice. (00:08:20)
Partners in Danger Chapter 9: The Haunting of Mary Jane - S4-E9
Continuity mistake: Mary Jane's gloves come and go when she's talking to Spider-Man on the rooftop at the end of the episode.
Sins of the Fathers Chapter 7: The Man Without Fear - S3-E7
Plot hole: They forgot Daredevil can sense when someone's lying, one of his powers. So, he should've known Spider-Man was telling him the truth about the computer disk.
Sins of the Fathers Chapter 7: The Man Without Fear - S3-E7
Continuity mistake: When talking with his father and Smythe, Richard Fisk's grey pants briefly turn into the same color as his suit jacket.
Continuity mistake: Kraven's arm band that he wears on his upper right arm switches to his left one briefly after he fights Spider-Man for the first time.
The Menace of Mysterio - S1-E5
Continuity mistake: Mysterio sounds cold and calculating in this episode. Yet in later ones he sounds different despite being voiced by the same actor.
The Sting of the Scorpion - S1-E6
Continuity mistake: The Scorpion gets bigger here, his eyes turn yellow, he gets fangs, his skin becomes sickly looking, and his fingertips resemble claws. Yet later on in later episodes he's missing all of that.
Partners in Danger Chapter 9: The Haunting of Mary Jane - S4-E9
Continuity mistake: Mary Jane's costume's gloves come and go between shots in Miranda's hideout.
Partners in Danger Chapter 9: The Haunting of Mary Jane - S4-E9
Continuity mistake: Miranda's pants legs go from both being torn to just the left one then the right one during her flashback.
Sins of the Fathers Chapter 7: The Man Without Fear - S3-E7
Revealing mistake: During the fight with Kingpin recycled footage is used from Season 1 Episode 7 Doctor Octopus: Armed and Dangerous. It's obvious when you see the background looking like the warehouse along with Doc Ock's machine behind Spider-Man.
Doctor Octopus: Armed and Dangerous - S1-E4
Continuity mistake: Doc Ock's left glove briefly disappears during his second fight with Spider-Man, and Jameson's pants are briefly his jacket's color during that fight.
The Menace of Mysterio - S1-E5
Continuity mistake: When Mysterio's unconscious he's in his costume. When Spider-Man leaves him webbed up he's wearing street clothes. But when he's shown on the headlines of the Daily Bugle he's back in his Mysterio costume.
Spider Wars, Chapter 2: Farewell Spider-Man - S5-E13
Revealing mistake: When Spider-Man is web-slinging with Stan Lee, they pass the same group of buildings twice, revealing it to be recycled animation.
Spider Wars, Chapter 2: Farewell Spider-Man - S5-E13
Continuity mistake: When Spider-Carnage has Gwen Stacy hostage, she is bound by portions of his symbiote. When Spider-Man frees her, she is suddenly bound by webbing instead of the symbiote.
Spider Wars, Chapter 2: Farewell Spider-Man - S5-E13
Continuity mistake: When Scarlet Spider is saying that they need to destroy the bomb, you can see one of the arms and tattered costume of the Man-Spider behind him, even though the Beyonder had already teleported Man-Spider to another dimension. It appears to be a shot from Spider-Man and Scarlet Spider's fight with Man-Spider that wasn't used and ended up being repurposed, rather than taking the time to animate a new shot altogether.
Spider Wars, Chapter 1: I Really, Really Hate Clones - S5-E12
Continuity mistake: When the group of Spider-Men are observing the Green Goblin and the Kingpin's henchmen from inside the ventilation shaft, the outside edge of the shaft cover is first shown to be on the wall outside of the shaft, and then inside the shaft itself when the Armored Spider-Man pulls the cover off.
Answer: Yes. Many things that would have been in the sixth season would have had Norman Osborne returning from limbo and reclaiming the title of the Green Goblin, Richard Fisk, the son of "The Kingpin" Wilson Fisk would return as a crime lord known as "The Rose", Ghost Rider would have appeared to help Spider-Man stop Dormammu from returning to Earth and Madame Web and Spider-Man would rescue Mary Jane from limbo.