The Return of Hydro-Man: Part 1 - S5-E7
Other mistake: When Spider-Man catches up to Mary Jane and Hydro-Man at the foundry, he webs up Hydro-Man's left wrist. When the shot changes to Spider-Man landing, he is not holding onto the web-line. When the shot changes back to Hydro-Man, his arm his pulled with the web-line remaining taut, even though Spider-Man is not holding the web. If Hydro-Man was moving his arm on his own, then the web-line would be slack.
The Return of Hydro-Man: Part 1 - S5-E7
Other mistake: When Spider-Man breaks the chain off the steering wheel of the boat, several of the links on the back loop of the chain break off, which would be impossible since he broke the chain at the front.
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.