Shout Out / Freeman's Mind

Half-Life 1

• A lot of them. Die Hard, Star Wars, Alien, James Bond, H. P. Lovecraft, Jurassic Park, Spider-Man, Super Mario Bros.... Gordon is a bit of a pop culture junkie.
• Players of Half-Life mods can notice clever references to mods.
• "I have no tail, and I must swing."
• Episode 5 had Gordon saying that manslaughter sounds like a butcher in a evil meat shop who grinds up people for meat.
• Episode 25 had him wondering if the aliens were in fact demons.
• "Dammit, I'm a doctor, not a... normal doctor!"
• "I need to talk to a lawyer, there might be some sort of Rambo clause."
• "Bugs can crawl on walls. Maybe I should have been a bug. Go team Kafka."
• "Roger, Roger. What's your vector, Victor?"
• "YOU SHOT ME IN THE EAR!"
• Freeman insults some soldiers by calling them "a bunch of Lemmings with machine guns."
  • He does the same thing with some of the scientists in an earlier episode: "Ugh, Darwin was right. I didn't realize I was working with a bunch of Lemmings."
• "We're the big shop of horrors."
• "Yeah, I'm a first generation Morlock!"
• "It'll be like that one scene from Scanners, except this'll be the real thing!"
• In episode 36, Gordon recalls the biology department making plants with killer pollen.
• In one episode, Gordon theorizes that he was supposed to die in the test chamber and everything that's happened since is the universe trying to kill him to put things right.
• "Maybe if something teleported inside of me I'd end up like THE FLY. Help meeeeee."
• "I mean, what is this, the The Three Stooges join the Corps?"
• "I bet that's how management thinks the elevator is run. A bunch of Oompa-Loompas inside the shaft singing while they move ropes and pulleys."
• "They'd call me Dr. Strangle-love."
• In episode 50, Gordon theorizes that ghosts let him out of the pipe like when they freed Jack Torrance in The Shining.
• When he encounters a giant, pointless gear in an underground waterway, he calls it a Charlie Chaplin cog.
• When putting together that Black Mesa may be about to suffer a meltdown in its nuclear plant he refers to it as China Syndrome.
• Gordon's favorite Dirty Harry movie is the one where he guns down the giant monster with the tentacle arms.
  Gordon: Make my day, squid-face.
• In Episode 59, the elevator music is a theme from The Sims.
• Unlike certain forms of teleportation, Black Mesa's teleporters don't conserve momentum.
• In Episode 67, Freeman wants the aliens to come out and play, in the same style that Luther calls to The Warriors, sans bottle clinking.
• Two towards Doctor Who near the end of the series: when dizzy on Xen, he glances at a glowing blue box and confuses it for the TARDIS for a second and calls the G-Man a Time Lord.
• Gordan's Hurricane of Puns at the dam references a similar series of puns spoken by the Hoover Dam tour guide in Vegas Vacation.

Half-Life 2

• Gordon describes the Breencasts as "Max Headroom for old people."
• Gordon mistakes a Strider for a Tripod and is worried that he's going to be capped.
• Gordon refers to the City Scanners as Servo-skulls.
• "You're like a magical white rabbit. That means I should follow you, right?".
• When Alyx makes light of Barney's reaction to Lamarr, Gordon berates her for it, describing what headcrabs do to people as 'Mind Rape', referencing both the trope name and the series that named it.
• After seeing the secret doors that lead into Kleiner's lab, Gordon starts humming the Get Smart theme tune.
• Upon encountering one of the game's several platforming sections: "Playing Frogger will save your life! Especially if you're a Cop Killer."
• "BIG BROTHER IS YOUR BROTHER, NOT MINE!"
• When Kleiner tells Eli that Gordon will be sent to Black Mesa East using the same teleporter as Eli's daughter, Gordon adds a gruff "We've come for your daughter, Chuck."
• He refers to the Civil Protection officers as Charles Bronson wannabes, referencing the plethora of movies where the latter played a Cowboy Cop.
• When Gordon first hears about the manhacks, he imagines them as Robby the Robot models from Forbidden Planet with machetes.
• In episode 4, he starts singing "Won't You Be My Neighbor?" of all things. Then the Metrocops bust in and start shooting everyone.
  Freeman: Nope, you're not a very good neighbor. Too much baggage.
• "Kill everything with barrels. This is Donkey Kong warfare."
• "This [alien invasion] is going to change science fiction forever. There's not going to be any more E.T. the Extra-Terrestrial or My Favorite Martian. People won't understand. E.T. won't be phoning home. He'll be waiting for you in a dark tunnel, ready to strangle you while he literally eats you alive. If you're lucky, he'll snap your neck first. People of the future will understand that."
• He concludes that Teenage Mutant Ninja Turtles correctly predicted Mousers. And Dimension X.
• "What kind of country gives its police guided missiles? That's literally more firepower than RoboCop!".
• Once Gordon starts musing about gnomes (again) while prowling the sewers, he briefly hums the Underpants Gnomes' song.
• Episode 8 starts with Gordon singing the Mister Ed theme.
• In the same episode he speculates whether or not this future is like Terminator, but decides it's not, because "I'm seeing zero AI progress." He later tells a refugee "come with me if you want to live."
• This season sees Gordon really double down on the Aliens references: consistently referring to the headcrabs as facehuggers, comparing the barnacles to xenomorphs when he sees their nested mouths, comparing the Combine's headcrab shells to Burke's attempt to weaponize the titular monsters, and so on.
• "Jumping gigawatts!".
• When Freeman first sees the Citadel, he compares it to the Tower of Orthanc.
• "What's happening is he [the G-Man] thinks he's Mr. Miyagi, and serving me up to the police is his interpretation of 'wax on, wax off'. Because apparently surviving Black Mesa and an alien world means I need to prove myself."
• Episode 19 has Freeman reference Assault on Precinct 13 (1976) albeit while being unaware of what film he's talking about.