Great game but need a couple pointers..

[Von Omar]

I agree with "sneak" being frustrating on walking targets. On stationary targets though I've had no issues.

I tend to use smoke to get moving targets to stay still for a moment.

As far as the demo goes, I usually just rush the primary target when he's at the rear of the base between the wall and that building. Nobody hears it (after removing the local patrols of course) and there is a truck handy. Just charging at him and stunning him is the easiest way. He whines about it of course, but the game still gives the option to knock him out, even when he's facing you and pulling out his pistol.
I wish that option was available on every target.