Remembering what was when over 45 episodes spread over years can be rough. Hopefully this will help you out.
'''Note: Astute gamers may infer spoilers from what is below. Everything is unmarked for ease of reading. You have been warned!'''
[[folder: Miscellaneous episodes ]]
* Episode 0: Freeman goes through the training course. Stops at the "Jump to Target" part as he doesn't want to be injured.
* Episode 10.5: Freeman messes up a jump, falls to his death.
[[folder: Before the event, episodes 1- 3 (Black Mesa Inbound, Anomalous Materials) ]]
* Episode 1: Freeman [[BlackMesaCommute rides the Tram to work]]
* Episode 2: Freeman finds his way down to work
* Episode 3: Freeman arrives at the test chamber and starts the "green apocalypse"
[[folder: After the event, 4- 13 (Unforeseen Consequences, Office Complex, We've Got Hostiles) ]]
* Episode 4: Makes his way out of test chamber.
* Episode 5: Freeman continues his way out of test chamber (to the lobby) and finds a pistol
* Episode 6: Jumps in a sewer, takes a lift that takes a long-ass time to go down, and gets stuck at a walkway
* Episode 7: Freeman plays Extreme Hopscotch
* Episode 8: Encounters bugs, electricity, maintenance shafts and a machine gun turret
* Episode 9: "'''Okay children, class is in session! Everybody take your seats! ''I said everybody take your seats!!'' Dammit Billy, that means you too!'''"
* Episode 10: Goes through a freezer section before finding a vending machine to get Doritos.
* Episode 11: Freeman hops over lasers and finds an [=MP5=]
* Episode 12: The "rescue team" arrives
* Episode 13: Freeman finally gets to the surface
[[folder: Freeman retreats back into the complex, 14- 24 (Blast Pit, Power Up) ]]
* Episode 14: Finds a shotgun, heads downward and takes a tram to a pool of "radioactive...crap"
* Episode 15: Arrives at the rocket testing engine
* Episode 16: Freeman wanders around silos and spots a large fan
* Episode 17: Returns to the rocket propulsion test chamber
* Episode 18: Restores all power to the rocket engine
* Episode 19: Finally fires rocket engine
* Episode 20: Jumps down a smoking hole where the alien used to be
* Episode 21: Encounters the large blue alien (Gargantua)
* Episode 22: Turns on the power generator for the tram
* Episode 23: Freeman makes it back to track control, only to realize power is still "off"
* Episode 24: Defeats the Gargantua and gets the tram working
[[folder: Begins the "On a Rail" areas, 25- 34 (On a Rail, Apprehension) ]]
* Episode 25: Goes around in circles on the tram, encounters a machine gun turret and ends up at a broken elevator
* Episode 26: Takes the tram back to the area with the crane and heads upwards (with the tram)
* Episode 27: Speaks like a pirate the entire episode
* Episode 28: Loses his tram (thanks to Rocky the Rocket Ranger) and is stopped by explosives
* Episode 29: Back on the surface
* Episode 30: Launches satellite
* Episode 31: Decides to head back down after being shot, takes another tram, and finds a big pool
* Episode 32: Encounters shark-thing (Ichthyosaur)
* Episode 33: Bypasses the giant pistons and discovers he's being tracked
* Episode 34: Ninjas, Gordon captured
[[folder: Post-capture 35-onwards (Residue Processing, Questionable Ethics, Surface Tension, Forget About Freeman) ]]
* Episode 35: Wakes up in trash compactor, can't remember who what he did yesterday.
* Episode 36: Wanders around the room full of canisters filled with the same radioactive crap, and gets lost
* Episode 37: Finally remembers what happened
* Episode 38: Rides conveyors
* Episode 39: Passes through Bio Labs, stops in lobby.
* Episode 40: Enters area with four lasers that converge into one
* Episode 41: Escapes Bio Labs, reaches Dam.
* Episode 42: "'''That ''Damn'' Dam! Damn.'''"
* Episode 43: Runs around in circles while being harassed by helicopter.
* Episode 44: Cliff-climbing, a rickety bridge, and a rocket launcher. Finally takes down the helicopter from the last episode.
* Episode 45: Freeman is [[MajorGeneralSong the very model of a modern major general.]]
* Episode 46: Dodges falling debris, avoids landmines, theorizes about alien gravity and the benefits of an extra finger, meets the sniper from Episode 31 again.
* Episode 47: Stumbles through the trip-wire maze, shoots an alien weapon dead, laments his inability to hotwire a military vehicle, and gets pinned down by a "[[TanksButNoTanks tank]]".
* Episode 48: After blowing up the "tank", Freeman plans to become the Film/LordOfWar, plays air traffic controller with a rocket launcher, and a guard learns the importance of knocking before opening.
* Episode 49: Freeman displays his skill in "shotgun chess" amid [[MeleeATrois alien vs soldier]] combat, considers if he has murdered enough people to alter the course of the timeline, and gets told to put a well placed satchel charge in his pipe and smoke it.
* Episode 50: Gordon almost shotguns another security guard, is disappointed in his lack of stamina and self-preservation instinct, and finally uses him as a decoy to escape another Gargantua. He also needs an airstrike map of the whole world.
* Episode 51: Freeman laments his OneManArmy status while navigating through Snark mines, only find himself at a dead end.