That was really good, but
your senses not can ever see the danger. In that part with the two doors i saw that blood on the right and think, there will be one. I go through the door in the middle and get killed by a Zombie. And that part when you see a monster going left you must have really good senses or you get killed by it. And the "Boss" was to easy. You must only shot at that thing upside it and it get killed.
Make another of it - but next time - please much harder.
;)