Shadow of the Tomb Raider

In the Main Menu, select the "Challenge Tombs" tab and then choose "Mother Protector." In the following menu, you can sift through three different modes: Exploration, Score Attack, and Time Attack.

In order to unlock this achievement, you will need to earn any medal in Score Attack. This mode is all about completing the Challenge Tomb (i.e. reaching the stele) all while collecting/shooting wisps of light to increase your score; the quicker you collect these items, the higher your multiplier and score. The medal requirements are as follows:

• Gold: 800,000 points
• Silver: 550,000 points
• Bronze: 200,000 points

As mentioned above, Mother Protector, while relatively short, is a semi-complicated Challenge Tomb given its puzzles. You should be able to net a bare minimum of 200,000 points without much issue, but if you would prefer to follow a video guide for assistance, please refer to THIS VIDEO, courtesy of KyoKat.