Yet another video guide:
I largely followed this guide, but varied on a couple things:
- before leaving the first area there's some explosive rounds (Raleken) for the Kampfpistole under the last car, be sure to pick those up
- when fighting the super solider, I used those Kampfpistole rounds on the super soldier.
- as soon as the super soldier dropped I picked up his chaingun & aimed for where the dog comes. As soon as the dog appears, let loose and try to avoid his attacks by strafing (which works like maybe 20% of the time)
In terms of my stats, I had 11,400 points before leaving the first area. I killed all 35 enemies, and got 25 headshots (5000 points) & 6 combo kills (1200 points), and in total 23,900 points (22,800 is the cutoff).
I think the key to this one is the first area: try to get as many headshots & combo kills as you can. If you find you're under 10,500 before leaving the 1st area you might as well restart as it's unlikely you'll make up for it in the later area.