Well...
Well you asked for some help on making a good horror animation, so here it is.
First of all, your atmosphere is TOTALLY off. You used some corny chase scene music while he was being chased by the killer. With a horror scenario, you should avoid using music as much as possible.
Try using a simple ambient track in the background, and rely on using sound effects to spice up the individual sections. This gives it a much more realistic feel, because in a real life situation, spontaneous music wouldn't start playing at any moment, but instead you would only be accompanied by the silence and stillness of your surroundings, and the noises you and your pursuer make, but to add to the ambiance factor you have a quiet track in the background giving off a creepy feeling.
Also, I would suggest you try and be more consistent with your graphics and animations. Sometimes your animations were very smooth and used plenty of frames, and then other times you used very few frames for a motion, and then sometimes you used very detailed graphics for your characters and backgrounds, and other times you used very simplistic graphics for your characters and backgrounds. It was all very inconsistent, and maybe it's just my preferences, but it bothered me. Another thing about the animations and graphics though, parts of them seemed very corny, such as when the guy dropped his cell phone. Maybe it was the fact that the music started at that exact point, but I think it would've been better pulled off with the character dropping his phone and slowly starting to back away with a look of horror on his face, then running off as the "chase" begins.
Another thing you should work on is your special effects. You already noted that you aren't good at blood, but that's even MORE reason to put alot of effort into the effects, including your smoke effect near the start, which wasn't very good either.
All in all, it wasn't perfect, and it didn't feel like a horror animation, but it was far from the worst thing on the site. It has alot of areas where it can be improved, more areas than I've listed, but you've got a good foundation here - Now do something good with it. Improve it, work on your atmosphere, spice up the story, get some voice actors, and you're golden.
As a final note I'd like to say I only really mentioned the negatives about the flash - It has plenty of positives as well, I'm just leaving you criticism on the parts I didn't feel were as good as they should've been.
-Frood
