Not Bad, I actually liked it. a lot.
Very good, but could use a lot more background music. Even if its very light background music, that's always better than an awkward silence which is unfortunately, your only reason for not getting a ten even though I feel that the overall idea, plot and animation truly deserves a ten.
I love how Brooks doesn't talk or seem much fazed about much but I do think he should at least make some sort of noise like breathing heavily or grunting after being directly attacked. I don't like the demon's design too much, but honestly I don't feel that I would be satisfied even if you gave him more detail :^P Sorry, I just don't think I could be pleased with the demon at all...
Otherwise, AMAZING JOB. The plot is interesting but not overbearing and the animation is solid and good. I love Brooks and really cannot wait for your next part. I hope we get to know more about the other men (like his killer and the other man who was killed)