There's 2 bad guys to fight, and an evil black spider man suit that Spider-Man literally cannot take off. It's like the director ran out of good ideas, and started copying Fantastic Four crap.
We also mused about what sort of accident during a scientific experiment would be cool for creating the bad guy in Spider Man 4.
Maybe there's some kind of nuclear lego factory and a crazy guy falls into a vat of lego plastic. And then when he comes out he's made of Legos and can shoot legos - and build stuff he needs by shooting them out of his hand.
Imagine the merchandising possibilities! Lego and Spider-Man already have a deal in place, so it'd be easy!