Just watched this. Had it's good and bad moments. Warning, huge spoilers abound.
So the film takes place a few months after Amazing Spider-man 1, or possibly a year or so on, since in the film, Peter Parker graduates from high school. His life seems to be going on pretty well, the public seem to love him, he's still wise-cracking and Gwen Stacy and him are getting along very well. But then he's also seeing the ghost of Captain Stacy (Gwen's father) everywhere, possibly as a sign of his guilt over his death and the fact that he's still dating Gwen despite the fathers dying wishes. Strangely enough, he never sees visions of Uncle Ben though.
So basically because this is Peter Parker, his life has to start taking a down turn. He breaks up with Gwen and a lot of the movie; one might even say too much of the movie, is taken up with their romantic 'will they, won't they?' subplot. Except they really have no reason not to so it's a pretty annoying subplot to have around just because the producers felt like having some romantic tension in the film.
Then there's Electro, the obsessive stalker/fan of Spider-man turned murderous psychopath. And Harry Osborn, Peter's childhood friend who just recently came back AKA as the Green Goblin. And the Rhino. Sorta. So basically, there's a fair amount of shit on Spider-man in this film.
Things I liked. Harry Osborn and Peter's friendship. The previous film series sort of made you wonder why Harry and Peter were even friends. The two weren't much alike and the longer they interacted, the more their differences stood out. In this one, Harry and Peter were childhood friends who hadn't seen each other in 8 years so when they meet up with each other, they pick up from where their childhood left out, which makes more sense.
However, the film has a lot of moments where you can really feel the deus ex machina in the plot. For example, when Spider-man refuses to give Harry his blood despite knowing Harry needs his blood to possibly save him from a life-threatening degenerative disease, he just refuses without saying 'hey, the last guy I gave my blood to? Turned into a giant lizard so...yeah, this might not be a good idea'. This causes Harry to basically go after Spider-man. Which leads to one of the bigger plot moments in the movie.
Then there's Gwen and Peter's moments in the movie. Holy crap, these people must be the MOST casual superhero couple in history. Not only do they reveal details of their personal life while in public places, they even do it while Peter is in costume. I'm sure no one can EVER track this back to Peter and Gwen... Seriously. They did this in ASM1 as well, what with Peter constantly taking off his mask as well.
However, one thing I didn't really like was Gwen Stacy dying. Yes I know she dies in the comics and I've actually read that storyline since I've read the Essential TPBs of the old Spider-man comics. However, that is that and this is an entirely new continuity. I just feel that while this keeps true to the spirit of the comics, it only helps alienate the normal movie watchers who had 2 movies to get attached to what they felt was the main heroine of the series only to have her killed off. Heck, Emma Stones Gwen was a way better character than Kirsten Dunsts MJ yet MJ survived for 3 crappy movies while Gwen doesn't?
And then there's the Rhino. Why the hell is Rhino even on the posters when he appears for maybe 5 MINUTES at the end of the movie? I'm not even counting the part where he appeared in the beginning as an unpowered non-supervillain. And the ending....just ends right before the fight between Rhino and Spider-man really begins. Wth? Granted, we know Spider-man is probably going to win and it does resolve his arc suitably since he regains his fighting spirit long enough to become Spider-man again after Gwen's death.
Overall, this is nowhere near as good as the last Marvel movie I watched, which was Captain America 2 (HAIL HYDRA) but I wouldn't say it's a horrible movie either. It's a pretty average superhero movie, much like the first was. You won't hate it but you won't really like it either. So overall, I guess it's worth watching.