Metro Last Light Redux SCRAM
Kill All Watchmen before they reach the Railcar
Metro Last Light Redux SCRAM – Achievement / Trophy Guide
While you are on the railcar, you will come to a point were you have to push another railcar in front of you. After you start pushing Watchmen will attack you and you have to prevent them from reaching the railcar. Use a long range weapon and military grade ammo and they will go down a lot faster. Also throw some fire grenades and weaken them while they are running towards you.