The Hero's Journey
published by TJ Horner
The hero's journey archetype is included in many stories, including the Portal and Half-Life series.
Part 0: Hero's Journey in Portal 2 (video)
I have covered the elements of the hero's journey in Portal 2 in the video included below.
After you're done watching that, I have included two write-ups below; one is describing the hero's journey in Half-Life 2 with the other connecting both of these stories back to The Odyssey.
Part 1: Hero's Journey in Half-Life 2
Half-Life 2 is one of the most critically acclaimed video games of all time. It set the standard for graphics, quality, and most importantly, story. That's what we'll be focusing on here.
Destiny
The game starts out with the main character and protagonist, Gordon Freeman, on a train about to enter the sinister City 17 controlled by Dr. Breen, who we'll meet later.

A monitor showing Dr. Breen's dictator-like face.
The Journey
You end up meeting Alyx, the herald and an ally. She guides you to the mentor, Dr. Kleiner. He could be classified as the "old man", although we don't know his exact age. He invented a teleportation machine to (theoretically) teleport you to Eli Vance's lab.
Kleiner's pet, Lamar, destroys the machine on accident and Gordon cannot teleport to Eli's lab. This is where he starts his journey. He has no choice here, but he does have Kleiner and Alyx to help him as he goes through City 17 to Eli's lab.

The destroyed teleportation machine.
The Boundary
At this point in the story, Gordon knows what his end goal is: get to Eli Vance's lab and stop the Combine (which are basically aliens, they aren't important to this) from invading Earth. The thing is, he needs to get out of City 17 and traverse the half-invaded Earth with him as an entire species' primary target.

Part of City 17.
The Journey Into Hell
Gordon is now tasked with navigating through City 17 and then into the wasteland to get to Eli's lab. With tons of enemies on his tail, he meets many allies from the resistance on the way.
These allies will help Gordon greatly throughout the story, giving him bits of information on what happened while he was in a deep sleep.

One citizen that is part of the resistance, along with a vortiguant, which is also friendly.
The Final Battle
After Gordon has met many friends and foes, he finally reaches the Citadel, the entry point of the Combine. In an attempt to destroy it before he goes to Eli's lab, he hopes to stop more Combine from entering and hopefully destroy all of them.
He ends up getting caught before he could reach the core and gets trapped. He has a new weapon, but doesn't realize it yet. He can use this to his advantage by picking up basically anything in the world, including energy balls which he uses as projectiles.

Gordon, trapped in a pod, looking at Dr. Breen and Eli Vance.
Gordon escapes the Citadel while destroying it. This leads on to Half-Life 2: Episode One, but that's a whole different write-up for next time.
Part 2: The Odyssey vs. Portal 2 vs. Half-Life 2
Element | Odyssey | Portal 2 | Half-Life 2 |
---|---|---|---|
Allies | Odysseus' men act as his allies, helping him along his long journey. | Wheatley and GLaDOS swap places for allies, but some other characters come in along the way, such as the announcer and Cave Johnson. | Alyx, Kleiner, Barney (not the dinosaur), and many others come to Gordon's aid when he fights through the wasteland. He is globally recognized and has many allies. |
The Journey | Odysseus and his men start with the city of Troy as their first journey. They end up taking many, many detours on the way back and lose many men. | Chell tries to stop GLaDOS then Wheatley after the weird character swap thing happens. In the end, she gets kicked out. | Gordon needs to stop the Combine from invading the earth, and he does so by taking a journey through the wasteland of what used to be normal Earth. |
Crossing the Boundary | This happens in many of Odysseus' stories along his journey, one being the goddess Circe. She tries to keep Odysseus from returning home by taking advantage of him. This creates a boundary, but eventually Odysseus takes hold of himself and continues returning home. | When GLaDOS is re-awakened, this creates a giant boundary in Chell's way. She must solve GLaDOS' tests to escape the facility, but ends up escaping with Wheatley without solving the tests. | Gordon overcomes many boundaries in the story, one being the broken teleporter. This was actually a proponent of his journey in the first place as well. He needs to find a way around to Eli's lab -- a detour. |
Foes | Odysseus gains many foes along the way, including (but not limited to!) Circe (in a way), the cyclops, Scylla, Penelope's suitors, and Apollo. He ends up fighting some, but not all of them. | Okay, this is a little weird. At first, Wheatley is your ally and mentor. Later on, after he gains power, Wheatley turns into a madman (madrobot?) and becomes your foe. But then later on, he tries to become your friend again. | Gordon has many foes including zombies, Combine, Metropolice, and many more. Way too many to cover! But he ends up fighting all of them and possibly wins. We don't know yet though, Valve hasn't released Half-Life 3. |
End
So there you have it. Wow, I'm finally done with this thing. I'm probably going to get a drink now.
Yeah, a glass of water sounds good.
Oh, wait, I forgot to put in the meme. Here it is:

The dankest of memes.