The feelies provided with this game included:
A pin-on button with "Don't Panic!" printed in large, friendly letters
A small plastic packet containing "pocket fluff" (a cottonball)
Order for destruction of Arthur Dent's house
Order for destruction of Earth written in "Vogon" (actually an English cryptogram written in a thinly-disguised Cyrillic alphabet. The text was nearly identical to that of the English Order for Destruction, so it was not hard to solve.)
Official Microscopic Space Fleet (an empty plastic bag)
"Peril Sensitive Sunglasses" (a pair of opaque black cardboard "sunglasses")
How Many Times Has This Happened to You?, an advertising brochure for the fictional guidebook/encyclopedia The Hitchhiker's Guide to the Galaxy
HHGTTG gained a reputation for deviousness. "The Babel Fish Dispenser" was a particularly tricky puzzle appearing very early in the game. Failure to "solve" the Babel fish puzzle did not kill the player, but rendered the remainder of the game unwinnable. That particular puzzle became so notoriously difficult that Infocom wound up selling T-shirts bearing the legend, "I got the Babel Fish!"
The Infocom version of Hitchhiker's Guide quickly became a fan classic; it 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. The game was re-released by Activision in several collection packages before rights reverted to Adams, enabling The Digital Village to re-release it as a web-based Java applet. Originally published as a fund-raising tool on the 1997 Comic Relief website, it took up permanent residence on Adams' own website the following year.