I'm 2 sessions in as a GM. It's quite early on, but, so far, the system is delivering. My group chose campaign play instead of cinematic, so the players are a little more cautious than usual, I suppose. Yet they come from a very move forward attitude and are not affraid of breaking bones (figurative or otherwise).
I generated a mission in the colonists table, designed a simple location for them to explore, based on the result, and seeded it with their personal agendas and two opposing, simple but hidden threats. Session #1 taught the players what their characters should know by heart: if the ship/station air system breaks, fix it ASAP. They first approached the problem as a regular dungeon exploration, but soon found out air from a VAC suit burns quicker than a torch. By the end of Session #2, they learned that managing stress is key to survive. If you panic, the odds stack against you real fast.
That's it for mechanics, so far. The players were already familiar with the basic task resolution and dice rolling of the system, 3/5 coming from a Tales from the Loop game. Free League did a great job here. The mechanics are similar, but the tone is totally different: Alien can be brutal (as it should) if you put your guard down.
The scenario works. Although everyone knows a little something about the movies, the book does a great job showing you the stories are more about low level workers trying to survive in deep space with inadequate gear, unbalanced odds and disposable lives (from the corporations pov).
Also, a xenomorph is a must in a cinematic one-shot, but not so much in campaign play. Anything you put against the characters is a threat, for a simple failed component in the ship/station can end up blowing the whole thing apart. A simple sabotage, a malfunctioning AI, a betrayal, a detour. I've found my players are expecting things to derail, and are more than willing to contribute to the mayhem with their personal agendas (gotta get that extra XP). Maybe I'm lucky. We finished a 14 sessions Call of Cthulhu game before starting Alien. By the end, they were smiling and laughing about their characters (mostly) miserable fates. I want to revisit CoC very soon, and establish a long-term campaign.
I guess the key to appreciate an horror game (or any genre, fwiw) is to be willing to play by the trope.