Be patient man. It can take a week before you start getting feedback, nevermind a few hours!I can use a little critism
Or is it just a lost case
As for the story itself, when you have characters talking, put what different person says on different lines.
Also why would they attack and kill humans if they did not betray the imperium? It still sounds like they have betrayed them.
You need to elaborate more. When you said "I looked around." instead of going straight to conversation you should say what you saw, get the reader to see through the eyes of the main character.