This is the third main game after Nemesis and Nemesis – Lockdown in the series. While the first two had characters be civilians that were thrown into a xenomorph situation, in this third game the player are Marines sent into a know xenomorph infested installation.

Again, the main rules are more or less the same as the first two games, with only minor tweaks here and there. This time, the board is built differntly (no fixed corridors like in the first two) which provides for random connections between the rooms in addition to the random room placement. Also, in the installation there is no oxygen supply at the beginning of the game, and the charactes carry oxygen with them. There are three sectors, each with an oxygen control room. As long as that has not been found, the characters have to spend oxygen each turn, or they'll suffocate.

The xenomorphs are again playing differently, and you get new character classes with new traits and advantages.

But basically still the same underlying game engine.