Given the overwhelming popularity of shockfests like Martyrs and the Saw series, the nearly universal disapproval of this film is itself shocking. It's strange how some films can make their mark for the very things that cause others to be rebuked. All Hallows' Eve is low budget and has its mistakes, but overall is a wonderful, very scary exploitation horror film with a memorable villain and surprisingly good production values.
All Hallows' Eve is an anthology film. Like most horror anthologies such as Tales From the Darkside: The Movie, Twilight Zone: The Movie, and Trick R' Treat, All Hallows' Eve has three main stories plus a wraparound story that ties them together. Director Damien Leone chose this format to showcase his pre-existing short films ("The 9th Circle" and "Terrifier"), so only the second story and the wraparound are totally new. The film opens with a woman babysitting two children on Halloween night and the discovery that someone has sneaked a VHS tape into one of the children's trick-or-treat bags. Reluctantly the babysitter plays the tape and the first of three stories begins.
With regard to reputation, there seem to be three primary complaints about the movie: 1) The director used previously created material, 2) The film is excessively gory, and 3) The acting is bad. Each of these is easily negated. First, most people have not seen the two short films, so the director seized his chance to have them viewed by a large audience. Completely understandable. Second, yes the film is graphic, but certainly no more than a hundred others released in the past decade, many of which were very popular. Third, the acting is actually pretty good. It's definitely strong enough to let the audience suspend their disbelief, which is after all the name of the game.
If there's one thing I've learned from reading reviews and posts on IMDb and elsewhere, it's that people will complain about anything. The truth is that All Hallows' Eve is a tense, entertaining horror film alive with creativity, realistic effects, and inspired direction. Its rating on IMDb (as of this writing) is unfortunate and unfair. If you want a polished horror film that's long on plot and every shot perfectly framed, see something else. If you want to have a good time and be scared, see this.