After getting safely aboard the ship, Arthur and Ford meet Ford's friend Zaphod Beeblebrox, who had stolen the Heart of Gold as his first act of office as the Galactic President, as well as Arthur's friend Trillian (Tricia McMillan), whom Zaphod had picked up from a party on Earth.

Arthur initially tries to help by supplying the Infinite Improbability Drive with a tea substitute from the ship's Nutrimatic device to serve as a source of Brownian motion, but this only causes Arthur to temporarily take on the consciousness of Ford, Zaphod, and Trillian in their respective pasts, and he must manipulate events such that items in these past periods are brought aboard the Heart of Gold in the present.

This requires Arthur to reach Marvin the Paranoid Android's closet on the ship in order to get the final tools needed to fix the computer and get it to land.

Once the player has acquired the eponymous Hitchhiker's Guide to the Galaxy, a wide variety of topics can be asked about, some of which may be helpful in solving the game's puzzles.

"[8] Jerry Pournelle advised non-readers of the novel against playing the game, and warned that "even if you've memorized the book, these puzzles are hard".

"[11] Adams stated that the puzzle's difficulty, and the notable game play change that it begins, was intentional; "Just as the player gets comfortable in the narrow neck, the bottom drops out!

[18][19] Video in March 1985 praised the game's fidelity to its source material, stating that "it survives the transition as wacky and spaced-out as ever".

Though acknowledging that "there may be a few minor problems with The Hitchhiker's Guide to the Galaxy", the reviewer suggested that "the game is so engrossing, funny, and often so infuriatingly difficult that you'll hardly notice them".

The magazine stated that Hitchhiker was "not your run-of-the-mill text adventure" but promised that "the puzzles are tough, but follow a certain capricious, twisted internal logic".

in June 1985 stated that the game "may well be Infocom's best effort to date", citing an effective adaptation of Adams's "comic absurdity", sense of humor, and "fascinating" story.

[25] The Hitchhiker's Guide to the Galaxy was one of five top-selling Infocom games to be produced in Solid Gold versions, with a built-in hint system not included in the originals.

Sporting a Flash user interface, and illustrated by Rod Lord (who also produced the guide animations for the Hitchhiker's TV series), it won the Interactive BAFTA Award for Best Online Entertainment.

This was due primarily down to the facts that there was "no solid game design, nobody to program it, and the backdrop of Infocom's larger economic problems".