(at around 39 mins) When Greta has an argument with her mother during the Dinner party, while the camera goes to her mother for the second time, the black woman on the right puts her glass of wine on the table and it doesn't make any sound. However when the camera faces Greta again the black woman (on the left side of the screen now) has the glass again in her and and puts it down again, however this time the glass does make a sound.
(at around 9 mins) During the graduation, while talking to Mark and Greta, Alice is seen holding the tickets to Europe before Dan has given them to her. They disappear for a bit and then Dan gives them to her a little later in the scene.
(at around 40 mins) When Freddy puts the first spoon of goo into Greta's mouth you can clearly see her spit it out, yet in the next shot of Greta her mouth is already full. And the second time Freddy puts something in her mouth the amount and color changes from the closeup of Freddy to the closeup of Greta.
(at around 1h 7 mins) After Mark is pulled into the comic book, and the whole place collapses a drip of blood falls on his head. In reality blood isn't that thick, and after Mark checks what it is the amount of blood on his cheek changes from the closeup to the wide shot.
(at around 27 mins) When Freddy is in the truck with Dan, and Freddy rips his own arm off, green ooze comes from the wound. But in the close-up shot, the "ooze" is now green sewn fabric, attached to the red and green sweater.
(at around 1h 16 mins) Near the end, when Freddy is holding Jacob's hand, you can clearly see Robert Englund's normal hand at the bottom of the glove. Freddy was completely burned so there should have been scar tissue instead of regular skin.
(at around 46 mins) When Mark dangles from the hole in the floor, he's holding onto the edge with his left hand, with his right hand free. When Alice runs to pull him up, she offers her right hand, and Mark can be seen reaching to her with his right hand. In the close-up shot that follows, it's Mark's left hand that grabs hers, and at an impossible angle. (Her right palm faces the screen, the top of his left hand also faces the screen - only possible if they were facing the same direction.) When the camera shifts position once again, his right hand is still not grasping the ledge, and she's pulling him up by his left hand.