Spider-Man 2 creators on game ending, post-credits and Spider-Man 3 hints
Presuming you're reading this because you got to the end of the main campaign, then you know that Harry Osborne is back in a coma after being separated from the Venom symbiote, and in an act of desperation, his father Norman Osborne makes a call to begin testing the G-Serum.
Additionally, blaming both of the Spider-Men for the harm that has befallen his son, Norman makes a trip to The Raft, where he has a tête-à-tête with an incarcerated Otto Octavius. When Norman notices Otto is working on something in a private journal he asks,"What are you writing?" To which Otto answers,"The final chapter." Ominous.
"From the tease at the end of the first game, we knew we wanted to be a story about Venom. We realised we needed that ending to be about Peter and Harry and Miles and MJ. That felt like a great setup for maybe a future appearance of the Green Goblin. "If you really think about Norman Osborn from the last three games, he's done a lot to hurt the city, but he's doing it all for the love of his son. At the end of this game, his son is now ostensibly taken away from him. So, we felt like we had a really good setup there to potentially kick off another story, if we ever decide to do something else with that character.