List of references to Aliens in the Halo series
From Halopedia, the Halo wiki
There are numerous similarities between the Flood and the Xenomorphs from the Alien series of films.
The Halo Array's effect of killing off The Flood's food source to starve them mirrors the purpose of the nuclear bombardment tactic to kill the Xenomorphs, as is described in Aliens tie-in novel Earth Hive.
Vehicles and technology
Story and characters
During the Flood-themed levels in both Halo: Combat Evolved and Halo 2—most notably 343 Guilty Spark and High Charity—visibility is limited, and close-quarters fighting is common, such that the player is forced to keep an eye on their motion tracker—a homage to Aliens. The same is true, albeit to a lesser extent, of some areas in Halo 3's Floodgate.
In Halo: Nightfall, the rocky, almost desolate terrain of Installation 04 has multiple visual similarities to the surface of LV-426 in Alien and its sequel Aliens. However, the terrain has a more significant resemblance to the surface of LV-223 in the film Prometheus, which is set around 20 years before the events of Alien. Coincidentally, Halo: Nightfall is produced by the director of Alien and Prometheus, Ridley Scott.
Several spoken lines heard in the Halo trilogy are taken from the Alien franchise. For example:
Halo: Combat Evolved
In some cases, Halo's Sergeant Johnson borrows military banter from other Aliens cast members.
The following dialogue occurs in the Colonial Marines dropship as they head toward the colony, before meeting the Xenomorph.
The following comical exchange in Halo 2 is a reference both to the exchange in Aliens and its replication in Halo: Combat Evolved.
Notice the similarity between the three conversations below, the former being from Aliens and the latter two appearing in Halo: Combat Evolved. In particular, note the jargon that appears in all three.
During the Campaign level Halo:
During The Maw:
The following dialogue occurs after the dropship sent to rescue the Colonial Marines crashes in spectacular fashion, when a Xenomorph butchers Ferro mid-flight.
The following dialogue occurs in Halo: Combat Evolved, after the dropship pilot informs a group of Marines that she is taking fire and can't rescue them from the Covenant ship they are now trapped on.
Tension builds before a dramatic "last stand" scene in Aliens, as Hudson sees a lot of activity on his motion tracker and famously utters one of the better-known lines of the film.
When the Master Chief first emerges to the surface after his first bloody meeting with the Flood only to battle more of them on the surface, Foehammer says,
In Halo 3, if Gunnery Sergeant Stacker is infected by the Flood, sometimes he mutters "kill me" or "shoot me", which is a line uttered at least three times in the Alien series by an infected host. Again, this may not necessarily be a deliberate reference.