8 min is a bit too long for my taste. Add a bit of special effects next time and maybe some third person camera shots (example you sneak up on a guy from behinds, switch to 3rd person and kick the back of his knees, arm around his neck and using one of those fake knives (that spring in) stab his skull)
Also, the sound effects for the gun were a little over the top. but I saw the hard work put into it and would like to see a shorter, better version.