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 2: Farewell Spider-Man - S5-E13
Character mistake: When Stan Lee is asking Spider-Man what he plans to do after saving all of reality, he responds by saying to find the real Mary Jane. Moments later in the final scene, Madame Web tells Spider-Man that she is taking him to find the real Mary Jane, which elicits an incredulous response from Spider-Man, as if he didn't know that was already the plan.
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.