Mission 1 S.S.D.D.
After completing the tutorial, you will head into the pit. BX's time is 19.7 seconds. This will take a lot of practice, but you need to focus on your accuracy and getting double and triple kills along your run. High accuracy will reduce your overall time. To help with this, I recommend taking the M9 and Desert Eagle pistols. This will take a bit of luck for the targets to line up for easy double and triple kills. Along the way you should beat 30 seconds and earn the Pit Boss achievement / trophy.
Here is a video guide with English commentary!
Here is a playlist of guides for this game!https://www.youtube.com/playlist?list=PL-HeW6XkKdUK97oYVSMU7...