Mothership is the best "Alien" RPG there is, because it makes you feel the same way people felt when watching that movie for the first time, even without a clue about what was "the Alien".
The problem with the Alien franchise is that we know everything there's to know about the threat, so we're just waiting for the characters to catch up.
If things go the right way, you never know what will happen. It is suspenseful in all the right ways and it strongly discourages encounters, way more than any Cthulhu games. You really feel like an ordinary joe in a very dangerous job, with a flimsy suit, facing unearthy horrors.
If the master can handle it well, I would say it was chest pounding.
Moths are such an interesting analogy for modern life:
In order to thrive during nighttime and avoid daylight predators, they have evolved a complex guidance sense based on stars and moonlight.
Then we invent artificial lights and fuck up 190 millions of years of evolution.
"Haha dumb bug is hitting the light."
"Hi, you have reached the Astral Plane communication line for Autumn the Witch. At this moment the line is busy, your call is important for us, you can make an appointment with our app. Please call again during the next blue moon."
Oh wow, TIL!