Evil Dead II ended with Ash being sent back to the year 1300 and getting himself captured by Lord Arthur's army. When Ash kills a deadite after being thrown into a pit he's welcomed into the army as a hero. Then Ash goes on a quest to retrieve the Necronomicon so he can get back to the 20th Century.
Ash's quest to retrieve the book is full of slapstick humor, including a fight with a clone of himself. Once he finds the book, in a reference to one of my favorite movies The Day the Earth Stood Still, he must recite "Klaatu barada nikto" and struggles to pronounce it correctly! Meanwhile the Army of Darkness forms, composed of ghouls and skeletons, it's a spectacular shot seeing all the skeletons advance in an homage to Jason and the Argonauts. The pre-CGI effects look pretty good, way more aesthetically pleasing than the Droid army in The Phantom Menace.
At 80 minutes (a lesson more modern movies should heed) Army of Darkness never lets up. The combination of action, comedy, and medieval set pieces are a visual feast. Bruce Campbell gives a physically demanding performance, while Raimi's direction displays a comic book sensibility, skillfully mimicking the pacing and imagery of a comic book.
Looking at contemporary reviews of Army of Darkness I'm surprised at the snobby attitude of mainstream critics - Roger Ebert, Janet Maslin, and Owen Gleiberman* to mention a few. They scoffed at the juvenile humor and the camp sensibility. Camp as defined by fellow blogger John Kenneth Muir "an aesthetic style based on a sense of knowing theatricality."** Going for artificiality instead of realism allows for double meanings and making light of the goofy tendencies of cinema. The Ash character is a great example of a Camp protagonist, transcending parody and entering into a realm of heightened reality. Army of Darkness holds up so well because it refuses to take itself seriously, winking at the audience and allowing them to join the fun.
Camp has fallen out of favor with modern audiences who prefer the Christopher Nolan brand of realism for comic book pictures. But the never ending stream of Marvel and DC movies are ripe for a blistering parody at some point - especially Nolan films. I cannot imagine Nolan doing Camp.
*I'm not someone who trashes critics or the critical enterprise. I've learned a lot about film by reading lots of criticism over the years.
** Susan Sontag's "Notes on Camp"