Another one of those easy to get trophies, but that is if you know the trick on how to. This is quite an easy achievement for you only need a couple of seconds in order to obtain this, twenty-one seconds to be exact. The goal is to keep your Berserk Active for that time and in one use. Just like the It’s All in the Wrist achievement, this can also be obtained in Infestation mode.

Below is a short guide on how to accomplish this:

1. If you don’t know how to use Berserk yet, it’s quite simple. Just hold and press (in campaign) or press (when it is selected in Infestation) whenever your nano charge is full.

2. On berserk, your character will turn blue and also all attacks will be stronger and faster. Berserk lasts for a few seconds, and every kill will reset the ‘timer’ for Berserk, so in order to get this, make sure you’re in an area with lots of enemies and make sure to kill an enemy every time the Berserk bar is almost out to reset it.

Hint: Most probably it will take about 8 Berserk resets to reach 21 seconds. Read “Haymaker” or at “Survive The Alien Onslaught” for a good location to do this.

Below is a video tout about the guide: