No it isn't original or scary but it's not bad First of all, regardless of the rumors there is nothing original about this movie at all. It is a mash-up of clichés. It is not funny and does not try to be funny. It is not anything at all like Evil Dead or its sequels. It is certainly not scary either. That said, it's still entertaining right up to the really lousy ending.
It starts off with some rather badly acted businessmen preparing for a big project at the work place. Then it cuts to the gathering of 5 stereotypical teens ready to head out to summer house for a little vacation. Others have already mentioned that the characters are very flat and the movie tells that they were chosen for that very reason. It also implies that there personalities have been altered with chemicals to make them fit more into their roles. There is the slut, the jock, the scholar, the fool -in this case a stoner-, and of course the virgin.
The businessmen in their control room plan every stage of the trip, watching the teens leave, having one of their own planted at the only gas station on the road, making sure the road cannot be tracked on GPS, and surrounding the area of the cabin with a forcefield so that there is only one way in which can be blocked so the kids can't get back out. They have the entire place rigged with cameras and electronics so that when the kids get to the cabin they can watch everything that happens.
The businessmen have arranged all kinds of stereotypical western monsters from horror movies ranging from good ole zombies to special redneck pain worshiping zombies. Some when you get the chance to see them are truly creepy like their nod at the Cenobites from "Hellraiser" and an evil clown a la "It". Some are just sadly lame like a Merman and a giant hissing Cobra.
The teens have to choose to go to the cabin then choose their method of death. The means of choosing is a cellar full of props. There is a dollhouse, diary, creepy old dolls, conch shell, and tons more stuff. The virgin makes the choice for the group unknowingly by reading from a diary. Yep, you guessed it... the redneck pain worshiping zombies it is.
Apparently there are ancient evil gods sleeping underground. For them to remain asleep, a ritual sacrifice has to be made periodically. The businessmen orchestrating the scenario with the kids in the woods are the ones entrusted to carry off this sacrifice. If they fail, the gods will awaken and destroy all humanity. Fortunately, there are rituals being carried out in other countries besides the US. Unfortunately all those have failed this time and it comes down to our kids in the woods. They must die and in the proper order or all humanity is toast.
Things seem to be going mostly according to plan. The zombie family finishes off the slut. The stoner gets pulled through a window by a zombie. The jock crashes his bike into the forcefield trying to go get help. The scholar is drowned when he and the virgin crash the motor home into the water. The businessmen go ahead and start to celebrate because the virgin's death is always optional as long as it is last.
The red phone rings. It would seem the celebration was premature. The stoner is still alive. Apparently the weed he is smoking has made him somewhat immune to the various chemicals they have been using to guide the teens in the choices they want them to make. He comes to the virgin's rescue and they run away into a mausoleum that leads to an elevator shaft.
At this point the movie goes downhill hard and fast. The ending feels like something just cobbled together to make a conclusion. The scenes are hectic and filled with torrents of gore. The story line is tossed aside for cheap action shots. The ending of this movie is probably the most unsatisfying ending in movie history.
The virgin and the stoner realize the elevator accesses glass cubes holding monsters and ghosts and that someone let the zombies they have been running from loose on them. The virgin realized she chose which monsters were unleashed on them because she read the diary out loud. Now they have to battle security forces armed with automatic weapons with orders to kill them. They hide behind a big console that controls the monster so she turns them loose. The monsters attack the guards then make their way through to whole complex slaughtering everyone.
Eventually after many corridors and rooms of gore, the two survivors reach the sacrifice room. The director of the complex who is played by Sigourney Weaver, explains that Marty, the stoner must die to save all humanity. She urges the virgin to kill him. After a struggle in which the director is killed, the two teens light up a joint and discuss how humanity is not worth saving as the ancient gods burst up from the ground under the cabin.
This moving is entertaining enough to watch once. I would wait to rent it or stream it rather than pay high theatre prices though. If you want something scary or funny, this is not the one for you. The first two thirds of the movie will appeal to those who like traditional teen slasher movies. Pretty much everyone will hate the ending.