Hey, I've been keeping up with the "FPS in real life" series. I've played them all. This is an improvment from your last 3 however it has its flaws.
Great concept, seen it before, but it doesnt get old.
Here come my greivences.
1) There's no health bar or ammo meter, it's not hard to make them. You've accomplished these flashes, I'm sure you can tackle that.
2) LIGHTING!!! I personally am an amature film maker, proper lighting is a MUST! The jump from dark to light takes away from the game. I suggest adjusting the exposure on your camera.
3) You re-use characters too much. Gather alot of people for these projects, or at least have them change shirts.
4) Your guns! Airsoft guns are a great prop, BUT! Paint or electrical tape over the orange tip. Also, in the very beginning it says "Picked up extra D. Eagle". That gun is not a Desert Eagle, it looked more like a Colt 226, or 9mm. to me.
5) Script. From what I've seen, it looks like you're improving. A short script with planned dialogue wouldnt kill you.
Thus ending my rant I have one thing to say, I like these game/interactive videos, but they do need some fine tuning