To start of the sound-design was very good. It helped set a scarry/creepy atmosphere. The wierd movement and anatomy of the assassin also made it al the more scary. Another good thing was how the animation played out. First we are introduced to a lady standing in a room with some corpses and dont know whats going on, but then the security footage is played and we now know the true nature of the lady and what presumably happend in the room that she is standing in. On the other hand the posses that the corpses are lying there look very much like ragdools and goofy which takes away from the atmosphere. The texts from the animation programm are also anoying as is the low frame rate. The facial expressions don't look genuin to me, so work on them and the lighting is also a little bad. But all in all it's not that bad. You obviously still have to work and your animation skills, but if this is one of your first animations then keep doing them.