Lost Contact is a DLC for Alien: Isolation which is basically a longer version of Survivor Mode. You start in a safe room, and you can choose between 2 missions in 2 different locations. One might be easier than the other, depending on your familiarity with the maps and play style. Of course, the Xenomorph and possibly other enemies lurk these areas. Once you complete 10, you can leave. Here you can play as Axel, a survivor and the first person from the station Amanda meets in the main game.
Compared to the previous Salvage Mode DLC, Safe Haven, I prefer this one. Mainly because we're more familiar with the character, and the levels are better-designed as well as being easier. That said, it's still pretty far from easy. You can save in-between missions at the cost of score, but I find the Survivor maps easier. If you like the challenge these maps bring you'd probably enjoy it, but if not don't bother. No new story content or achievements.