Sam Raimi's film accomplishes a lot with his camera work. Giving the demon the first person point of view with a jerking camera speedily chasing Ash through the house allows the demon to have a force on screen that is violent while being unseen. This use of the camera to reveal the antagonist saves on special effects in a major way and Raimi's use of tearing down doorways in new ways adds a lot of production value to the film as well.
Raimi also has a great shot in the barn after Ash has killed Linda for the second time with the chainsaw where the lightbulb gets smothered in blood and turns the light from golden to red. It reveals how Ash sees the world is going to be different from here on out. He's gone from a romantic weekend with Linda to murdering his demon possessed girlfriend.
Most notably Raimi wanted to send Ash through time to the Middle Ages. He knew this during pre-production on The Evil Dead. Knowing this, the script for this film moved towards this happening to the character which is fulfilled when the incantation sucks Ash and the demon back to 1300 A.D.. This sets up the opportunity for the third installment of the film series with Army of Darkness.
