Well... that was disappointing!
Even a person who hasn't read the manga can tell that this OVA is as much of a horror as Tim Burton's Nightmare before Christmas is. Actually, that is scarier.
As many people so fabulously fail to understand what horror is, let me explain - it is what makes you have a ducked up dream the next night, or two, or thirty and what makes you scared to go pee by yourself in the middle of the night.
That being said... this would make an awesome comedy! No, despite my playfulness here, I am not joking. Just imagine Benny Hill music playing while that slutty girl with unmemorable name is chasing Aki down the street - three different scenes, in which both of them are running slower and get tired. Or in that scene where the shark is chasing those two down the street! Or any chasing scene at all! But no - all the while, epic divine music in the BG and some serious lame story exposition.
Needless to point out, makers of this crap thought they could get away with bringing in the very smexy scenes of a girl being done by two guys, her gorgeous underwear and her legs spread far and wide. Now THOSE were scary, am I right?
And how about that whole "let's totally switch the roles here" thing? Instead of watching a smart guy uncovering the truth bit by bit, struggling to help his annoying girlfriend and dealing with crap from his uncle, we watch that same annoying girl wailing and being irritating as duck. Characters are such a delight! Did I mention the slutty girl who is in no way useful to the plot? Or that fatty one? And I am serious. They have ABSOLUTELY NOTHING to contribute to this story.
What can I say about the sound section? First VA aren't bad. No, I'm serious. Considering what they were asked to do, they did their job fine. Sure, the script was a disaster, but voice acting was fine.
Oh but then! They used the most epic music they could pull of for a scene of a walking rotting shark attacking people. Surely not the scary silence, the dramatic DUNs DUNs, or anything that send a chill up your spine - nope, we're listening to soundtracks of The Elder Scrolls games.
To finish off, even fancy art and pretty good animation, which made it pretty attractive to the eye, couldn't save this poor, poor anime. I bet Ito-sensei (the mangaka and original creator) facepalmed upon seeing this.
Conclusion: I'd much more enjoy watching Ryuk chasing apples while they are playing unfitting music in a loop on Youtube.