Limb Hunter

You need to go back a couple of areas and then drop down to open a lever to a location under where you fought the dozer boss to pick up the blue access card.

Here's a full video walkthrough that shows all of the achievement for title update 2:

If you had picked the Blue Access Card prior to the Title Update 2 release, the achievement should auto-unlock upon updating and booting the game.

If not and if you are picking up where you left off at the end of Title Update 1, you are going to need to backtrack two areas. It will be located beneath the exit of The Monument.

Once you see the gap, drop down until you see the lasers. Lower yourself down using the lasers until you can go left. Keep heading left until you reach a lever. Pull the level to get the gate open to where the card is. Head back the way you came and grab it along the way.

I just prepared a Video Guide for the 3000g Update. You can get this done as quick as about 20 Minutes. Most of the new achievements are missable

TIMESTAMPS:
Intro - 0:00
Achievement Breakdown - 0:07
Upgrading Character and 3000 Gears - 0:48
Blue Access Card - 3:14
Green Access Card - 7:18
Secret Gate - 11:04
Secret Lab - 12:28


VIDEO GUIDE: