Call of Duty: Modern Warfare 2/Sniper Fi

Wave 1

 * 15 Hostiles

Start off by looking behind you and getting the claymores and the M240 with heartbeat sensor. Plant one claymore near the ladder to the roof of the building you start on and place another at the top of the stairs. Lie on the ground to the right of two boxes and start sniping the enemy, the first wave is the hardest. Occasionally check your heartbeat sensor to see where the remaining enemies are, pay careful attention to see if they are behind you. If they are, get the machine-gun and kill them then continue sniping until the end of the wave.

Wave 2

 * 20 Hostiles
 * 1 Jeep

A predator control unit will appear on top of the two boxes, pick it up, go prone and use it straight away. Make sure you are out of the line of fire, because the missile will go out of control if you get hit. You get an unlimited number of these missiles but after using one, you may not launch another for a set period of time. Aim for the Jeep with the missile then continue sniping the enemies until you get another predator and use that to finish off the remaining enemies.

Wave 3

 * 23 Hostiles
 * 1 Troop Transport

Continue sniping and using the predator on vehicles first. The faster you launch the missile, the more kills you usually get.

Wave 4

 * 24 Hostiles
 * 1 Jeep

Continue using the Predator Missile and Sniping.

Final Wave

 * 30 Hostiles
 * 1 Jeep
 * 1 Troop Transport

Try to hit the Jeep and the truck with the same missile for a lot fewer enemies to deal with. If this fails then destroy the truck first. As there are more enemies, be careful about behind you.