With a bit of time and better planning, it could have been a great movie. Venom's inclusion felt like a studio mandate they had to work around, the story with the Sandman I thought was reasonably well done and I suspect could have been much more poignant.
They seem to be going for something like The Spectacular Spider-Man cartoon's plot, with Oscorp shelling out supervillains for its own profits and it coming back to bite them in the butt.
I think that's going to be a pretty common occurance, games are looking more like blockbuster action movies and blockbusters are getting their inspiration more and more from video game cutscenes. I guess that's the inevitable conclusion to the film medium's marriage to CGI.
I hope they do something different with Harry Osborn's character than just making him the pathetic frenemy. I never felt the Norman/Harry/Peter dynamic was the right way to go with the characters, Stan Lee liked using the few characters he had any interpersonal relationships with as either villains or fodder for villains, and it just cemented the sort of persecution complex Spider-Man has in the mainstream Marvel Universe. Had they'd done what I believe Ditko wanted, making the Green Goblin a random stranger, it would've created an important theme that crime is often faceless and impersonal.