Factual error: Several episodes depict the moon in the night sky as being far too large.
Other mistake: Spider-Man is shown web-slinging past several glass buildings, but he does not cast a reflection in any of them. (00:00:10)
Deliberate mistake: When the sewer worker is trying to escape the Lizard, the fast lanes in both directions of traffic are visibly clear for several blocks, which is extremely unlikely in downtown New York. (00:01:10)
Continuity mistake: When Peter and Debra are approaching Dr. Connors' office, the nameplate on his door misspells his name as "DR. CURT CONNeRS". After they have entered the lab, the nameplate is shown to have the correct spelling. (00:06:10)
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: Mysterio sounds cold and calculating in this episode. Yet in later ones he sounds different despite being voiced by the same actor.
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.
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.
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 Alien Costume: Part 1 - S1-E8
Audio problem: When John Jameson is inside the crater, his mouth is not moving for any of his dialogue. He's communicating with the other astronaut, so it can't be an inner monologue. (00:01:05)
The Alien Costume: Part 1 - S1-E8
Audio problem: When Eddie Brock is complaining about being stuck in traffic, he hits both of his fists against the handle of his car's steering wheel and somehow the horn blows. (00:03:00)
The Alien Costume: Part 1 - S1-E8
Audio problem: When the field reporter is saying "The shuttle is headed for the greater metropolitan area," his mouth movement does not match the word "metropolitan." (00:04:15)
The Alien Costume: Part 1 - S1-E8
Other mistake: After tricking police by disguising himself as a policeman, Spider-Man changes his clothes in the middle of traffic with numerous people around but somehow nobody notices this.
Other mistake: Despite being Shield agents the guys shown in the target practice room wear the same uniforms as the guards working for The Kingpin.
Neogenic Nightmare Chapter 1: The Insidious Six - S2-E1
Revealing mistake: When Rhino walks out of his cell, his left arm passes through the cell door.
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Continuity mistake: When the X-Men are approaching Spider-Man, the neck portion of Gambit's headgear is flesh-colored. (00:01:45)
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Continuity mistake: When Spider-Man is battling the X-Men, he shoots webs at all of them, which they remove. Later when Spider-Man is in Xavier's study with the X-Men, Gambit is shown removing a piece of webbing from his right arm, even though he had already removed it earlier. (00:02:15 - 00:04:30)
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Continuity mistake: When Professor X is explaining his line of work to Spider-Man, the neck portion of Gambit's headgear is flesh-colored. (00:04:35)
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)
Neogenic Nightmare Chapter 4: The Mutant Agenda - S2-E4
Audio problem: When Spider-Man is saying to Beast "I'm not sure I still am," Beast is the one mouthing the last three words in the line. (00:09:25)
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.