Night Terrors Achievement
Finish the Campaign on Ultra Nightmare difficulty
Ultra Nightmare is the highest difficulty that is available, right after Nightmare. This achievement is for completing the base campaign on Ultra Nightmare, not just the DLC. If you have completed the game's campaign already, you'll have to complete it a second time on Ultra Nightmare. There isn't much a difference in difficulty in comparison to Nightmare mode. The same rules apply;
- Make sure you're stocked up on Medkits.
- Watch your defib bar.
- Don't rush into battle.
- Make use of cover.