Many will lump this into the sequels of Stephen King based movies, which is correct. This one was not written by King, but despite this lack of originality it is a fairly good sequel to an excellent movie.
The mood is dark, just not as dark as the first film. We have Geoff and his veterinarian dad relocating to rural Maine (and the location of the Pet Sematary) after Geoff's mom is accidentally killed in front of him while shooting a movie. In their new small town, Geoff's dad opens up his own practice while Geoff has trouble adjusting to his surroundings. He befriends another outcast, Drew, who has an abusive stepfather named Gus to deal with at home. One night, out of meanness, Gus shoots and kills Drew's loyal dog Zowie. Drew then gets Geoff to help him bury Zowie in the notorious cemetery in hopes of bringing his dog back to life. It comes back, just different, mean and nasty, like it's mad about being resurrected and now hates everything and everyone (like all things brought back to life in the cemetery act). This starts off a chain of events that leads to the destruction of the lives of everyone involved (and some who aren't involved incidentally). Now its just a matter of who can survive the supernatural terror engulfing the town. The storyline is fun and the acting is good enough. The gore and other special effects are great.
I can easily look past the bad points in a film and see the good in it. This film is like that for me. The film also posses qualities that make me automatically like it. It is an underdog film (meaning it's not very popular with most people on this site). It also has that early 90s disillusioned grunge youth generation feel to it. Some may see this quality as making the film darker, even mean-spirited, but I love that era and love its influence in movies. This is just the frosting on the "cake" for me, and overall the "cake" is worth a viewing on its own merits, even if it's just so you can judge for yourself.