Metro: Last Light Redux

So here is a guide if you are looking to get this achievement quickly without having to play through the whole story. I played through about 7 missions getting 45 mutant kills with quite a few hours of game play, as there really aren't that many mutants, at least with the missions I played through so far.

You will have to play through at least the first mission or two to be able to get the chapter select option in the main menu (I assume, as most games won't let you chapter select until you have completed a couple chapters). In the Chapter Select Menu press X for "New Missions". Go down and select "Developer Pack".

Once in this level make your way towards the Arena. Just outside you can choose whatever guns that you wish to use (I suggest automatic weapons because you can kill multiple mutants quickly with one clip and there are ammo boxes with unlimited ammo, but if you want to have fun with a shotgun or work on your precision shooting, then go for it, because it is pretty easy). Now inside the entrance of the Arena there is a console you can interact with by pressing X. I clicked on Watchman I believe 4 times to keep spawning more until I was unable to click on it any more. Then select Begin Combat and just start killing. I got 61 kills in about 5 minutes or less before they stopped spawning. Just rinse and repeat and you should get the achievement in 10 minutes or less after unlocking the Chapter Select option.

I hope this guide helps those trying to get a fairly quick achievement. If there are any flaws or better suggestions for this guide, please comment so I can make any adjustments to improve it.

No matter what ending your going for you can kill most mutants and not get bad moral points.

Here is a guide that will help you skip the bad moral points http://metrovideogame.wikia.com/wiki/Moral_Points.

Other than that you will get it by the end of the game if you kill everything in your path.