Factual error: Several episodes depict the moon in the night sky as being far too large.
Sins of the Fathers Chapter 8: The Ultimate Slayer - S3-E8
Factual error: Despite being a paraplegic, when Smythe is about to be lowered into the vat of chemicals, his legs are pretty toned and muscular. The show implies that Smythe had been wheelchair-bound for a long time, so even if he had muscular legs prior to his paralysis, the muscles would have atrophied.
Sins of the Fathers Chapter 3: Attack of the Octobot - S3-E3
Factual error: When Spider-Man and Doc Ock are talking in the lab, at one point, a shot of Doc Ock's face shows Spider-Man reflected in each side of his sunglasses. However, Doc Ock's glasses have a singular lens, and the straight angle of Spider-Man's reflections suggest that the glasses are in no way curved, so Spider-Man should only be reflected in them once.
Sins of the Fathers Chapter 1: Doctor Strange - S3-E1
Continuity mistake: When Peter wakes up from Baron Mordo's illusion, he is wearing a monk's robe with sneakers and is barehanded. He removes the robe, revealing he was wearing his Spider-Man costume underneath, but his gloves and boots magically appear on his hands and feet as well. (00:09:45)
Neogenic Nightmare Chapter 5: Mutants Revenge - S2-E5
Continuity mistake: The size of the hole that Wolverine climbs through increases drastically. (00:07:45)
Secret Wars, Chapter 1: Arrival - S5-E9
Continuity mistake: Towards the end of the episode, Captain America stands up to pledge his support to Spider-Man. When the shot changes, Cap is suddenly sitting down. When the shot changes again, Cap is standing up.
The Return of Hydro-Man: Part 1 - S5-E7
Continuity mistake: When Spider-Man is in the lab analyzing Mary Jane's jacket for clues, the inside of the door to to the lab has the door knob on the right side. When Debra Whitman is trying to get in the lab, the door knob on the outside of the door is on the right side as well, when it should be on the left side. The inside knob also disappears when the security guards break the door down.
Secret Wars, Chapter 3: Doom - S5-E11
Continuity mistake: After the Beyonder ends the war, he teleports everyone to a floating chess board in space, with Dr. Doom lying near the edge. When the shot changes, Doom has moved closer to the middle of the board. He is unconscious so he couldn't have moved.
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.
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.
Partners in Danger Chapter 8: The Return of the Green Goblin - S4-E8
Continuity mistake: When the Green Goblin is first confronted by Spider-Man, he is riding his regular glider. Then after he pushes Spider-Man down onto the roof, one shot show him riding the larger glider.
Six Forgotten Warriors Chapter 5: The Price of Heroism - S5-E6
Continuity mistake: When Captain America is giving Spider-Man moral support after Mary Jane's accident on the roof, the red glove on his right hand briefly turns blue when he puts his hand on Spider-Man's shoulder.
Six Forgotten Warriors Chapter 5: The Price of Heroism - S5-E6
Continuity mistake: When Captain America and Red Skull are grappling near the vortex, their fingers are interlocked. When the shot changes, their hands are pushing against each other's torsos.
The Wedding - S5-E1
Other mistake: When J. Jonah Jameson is on the phone with Wilson Fisk, one shot shows that the area of Jameson's desk between the receiver and the cord is colored the same gray color as the cord, instead of the golden-brown color the rest of the desk is.
Partners in Danger Chapter 5: Partners - S4-E5
Other mistake: When baby Silvermane is secured to the platform, his arms are long enough to reach inside the restraints. Considering he is physically a baby, the mistake is that the animators either goofed and drew him to be a little older, or that his arms are disproportionately long.
Partners in Danger Chapter 4: Return of Kraven - S4-E4
Continuity mistake: When Kraven is climbing the cage, it briefly changes color from silver to red.
Sins of the Fathers Chapter 3: Attack of the Octobot - S3-E3
Continuity mistake: When Doc Ock is about to unmask Spider-Man in his lab, there is a brief shot of Doc Ock standing under a night sky. This is from their rooftop battle in the previous scene/episode.
Six Forgotten Warriors Chapter 4: The Six Fight Again - S5-E5
Other mistake: The news footage of the elderly Six American Heroes being attacked by the Insidious Six is merely clips from the previous episode.
Partners in Danger Chapter 6: The Awakening - S4-E6
Continuity mistake: When Morbius is battling Spider-Man and Black Cat on the rooftop, his red eyes are colored white in a couple of shots.
Partners in Danger Chapter 5: Partners - S4-E5
Continuity mistake: When Smythe is discussing his plan with the Silvermanes, his yellow eyes are blue in one shot.
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.