The comic is illustrated with screenshots of characters posed using Garry's Mod, a tool which allows manipulation of the Source engine used by Half-Life 2.

[2] Livingston also reported positive reception from staff at Valve, the developer company of Half-Life 2, who were pleased to have a comic based on their game.

He had previously considered developing a webcomic that would parallel the storyline of the original 1987 Legend of Zelda, for the Nintendo Entertainment System, from start to finish.

He chose the Half-Life 2 game world as the scene for his comic because he was a fan, and because the availability of Garry's Mod eliminated the need to draw by hand.

Throughout the game, the player follows the story of a dark, dystopian future in which mankind has been enslaved by the Combine, a mysterious alien enemy.

In contrast, Concerned follows the same general path through the story established by Half-Life 2, but instead follows the adventures of Gordon Frohman, a hapless, lethally clumsy oaf who arrives in City 17 a few weeks before Freeman.

Frohman is incredibly naïve and, unlike the other citizens, seems to enjoy living under the rule of the totalitarian administrator, Dr. Breen, and the Combine.

Demanding to become one with the Combine, Frohman willingly sets off to Nova Prospekt, an alien security and detention installation, for invasive surgery to convert him.

Traveling through City 17's canals, Frohman arrives, badly injured and dazed, at Black Mesa East, the headquarters of the human resistance, where he is welcomed as a helper.

On Frohman's arrival, Ravenholm is depicted as a peaceful, bright, and cheerful place devoid of any Combine elements, but "terrorized" by Father Grigori.

With Father Grigori's help, Frohman escapes Ravenholm, now the zombie-infested nightmare seen when Freeman visits it in the game, and presses on to Nova Prospekt.

Here, after passing the final resistance base and an Antlion-infested beach, Frohman encounters an Antlion Guard, which is killed by a Vortigaunt, an alien race helping the humans in the game.

Baffled by his ability to survive, he realizes through a flashback that he has been under "Buddha Mode", a cheat code which prevents his health points from dropping below one throughout the comic's duration.

Frohman inadvertently turns off the mode, and even spoils an opportunity to be rescued by a group of Vortigaunts, as both Gordon Freeman and Alyx Vance are at the start of Episode One.

He emphasized the presence of various objects throughout the levels of games which were intended to aid the player, but would have little chance of being found in the real world in a similar manner.

It just seemed like a good setting to make jokes.Much of the comic's dark humor is derived from its contrasts with Half-Life 2: in a depressing, dark vision of a conquered humanity's future, Gordon Freeman becomes a hero and savior; the similarly named Gordon Frohman, on the other hand, is just an average person, improbably cheerful to the point of stupidity, and somewhat naïve as to what is actually going on around him.

He accidentally gives Breen the idea of headcrab shells while on a radio,[‡ 13] and sets up all of the traps in Ravenholm himself in an attempt to catch Father Grigori.