Oh, well yea. It's based off of Evil Dead, a very classic -old- horror movie. It was so terrible, many people took it for a comedy. They eventually re-made it to be a funny/horror movie, and thats kinda what this video is based off of.
Plus, on top of that, Lordi is alot like Gwar* in the sense their music and appearence is supposed to be funny, rather than hardcore super evil demon... things... It's all in good fun.
*(Another band that dresses up in demon costumes)