[6] Written by Ragnar Tørnquist, the story sees players assume the role of a young art student who is thrust into an emerging situation that seeks to undo a delicate balance that has kept two worlds separate.

The Longest Journey is a point-and-click adventure game where the player interacts with objects on the screen to solve puzzles and advance the story.

The protagonist, April Ryan, is an 18-year-old art student living in Stark, identified as a 'Shifter' capable of movement between these worlds, and tasked with restoring their essential Balance.

When surreal activity begins affecting her friends, April meets again with Cortez, who transports her to the Arcadian city Marcuria.

Later in Arcadia, April meets the innkeeper, Benrime Salmin, and the clairvoyant Abnaxus, ambassador of the Venar, who identifies the coming danger.

Before departing, she learns that she must defeat an alchemist named Roper Klacks, in order to free the ships' wind that he holds captive.

En route, April kills the monster known as 'Gribbler' while rescuing one of her captive Banda, whose species later give her the name 'April Bandu-embata' as a mark of gratitude and grant her part of the disc necessary to restore the Balance.

Returned to Stark, April gives Flipper the star map to decipher, infiltrates MTI, and is captured by antagonist McAllen.

Retrieving the disc and the four jewels, April returns to Flipper, whom she finds dying after the seizure of her deciphered map by Gordon Halloway, and gains a copy from him, which she uses to locate the Guardian's Realm near the space station 'Morning Star'.

On her way to the Guardians' Tower, she imprisons the Chaos Vortex in her Talisman and later summons Crow, who helps her complete the necessary trials.

Inside the tower, April re-unites Halloway with the Chaos Vortex to restore his candidacy as Guardian and returns to Stark and Arcadia.

In the Epilogue, the scene returns to Lady Alvane's home, where she has narrated the entire story to two youths, and where she reveals that the two worlds re-united under Gordon Halloway.

Upon their departure, an aged and graying Crow enters, asking the tale of the "warrior princess" who won the war of the Balance, and she corrects his impression; a possible reference to the sequel, Dreamfall: The Longest Journey.

"[citation needed] Other inspirations for the game included Gabriel Knight: Sins of the Fathers, Neil Gaiman's The Sandman and The Books of Magic, Hellblazer, Swamp Thing, Buffy the Vampire Slayer, and Joss Whedon's writing in general.

GameSpot called it "one of the best adventure games in years" and applauded the "complex and interesting story", but found the ending lacking as "the epilogue does little to wrap everything up".

[20] IGN said the game "actually reinvents how stories can be told in the medium" and noticed the mature content, including "harsh subject matter, and some big time swearing".

[23] The US edition of PC Gamer praised the "mature and magical" story, the "sumptuous" graphics, and the game's puzzles.

However, for anyone willing to give it half a chance, the game can provide the same kind of enthralling entertainment as the most meticulously crafted mystery novel or film, perhaps even rekindling a lost sense of wonder in the way reality really works.

Its target demographics were outside the industry's norm: Ragnar Tørnquist reported that Funcom wanted to capture "a more adult audience in addition to the usual teenage buyers".

[38] According to market research firm PC Data, North American sales of the game reached 12,495 retail units by the end of 2000, of which 10,873 were sold in December.

[46] Ragnar Tørnquist noted in 2003 that he was "very satisfied" with the game's sales in North America, and explained, "There was such strong word of mouth, and so many great reviews, that we managed to get TLJ into most big stores and out to the players regardless of marketing.

[49] In 2019, Tørnquist recalled that "at least 50 per cent" of the game's players were female, a fact that he believed increased its commercial success.