Mostly Humorless It might have been hip to be a fan of this series back in 1981, but it hasn't aged well. There's so much wrong, it's hard to know where to start.
How about the plot? First episode actually starts well, mild-mannered Arthur Dent is understandably shocked when his friend Ford Prefect reveals he's an alien, and the Earth is about to be destroyed to make way for an intergalactic highway bypass. There's some suspense, then it actually happens. It's a bold way to begin a sci-fi series. Then the pair escape into space, and the plot grinds to a crawl, meandering around. Very little makes any sense. Arthur and Ford hitch a ride on a Vogon ship, then are ejected into open space, but saved by another passing space ship. Here they meet the two-headed Zaphod Beebelbrox and his assistant, an Earth girl named Trillian. By amazing coincidence, they've all met before. Zaphod is supposed to be some suave, debonair adventurer and thief. Instead he's just a shallow goof. The group have various adventures until it all ends abruptly after six episodes.
Characters are poorly written with little development. About 90 percent of Arthur Dent's dialogue is asking questions with an astonished expression: "The Earth? Mice? Mice?", and so on. Ford acts cool and nonchalant in every situation, as if this happens to him daily. Very little is explained clearly. We do know that aliens are interested in Dent's brain, which may hold the secret to the question of life, the universe, and everything. Since we learn that Earth was built as a giant computer to determine this, the last Earthling could be the key. But isn't Trillian also from Earth? Plot holes like this are ignored.
Things happen randomly, just to transport the group to another scene. An explosion doesn't kill them, just throws them forward in time to a restaurant where you can dine and witness the end of the universe. This is all intended to be comedy and satire, but there's not much laughs or insight here. The humor is very dry and absurd in Monty-Ptyhonesque style, but not nearly as funny. Everyone we see has odd character quirks, like a robot assistant with depression. Isn't it hilarious? There's no comic payoff to this, or anything. Many plot points are setup and forgotten. Ford tells Arthur to always carry a towel when in space. And then what?
Even the Hitchhiker's guide to the galaxy is barely mentioned after the second episode. It appears in short animated segments to provide exposition, nothing more.
By the last episode, the foursome teleport off a stolen spaceship, and Zaphod and Trillian vanish from the story without explanation. Arthur and Ford go back in time and space to prehistoric Earth, where they learn history will just repeat itself. The pair shrug and walk off together, with nothing resolved.
I know, some will say this is all expanded on in Douglas Adams' books this series is based on. But you shouldn't have to read a stack of novels to make sense of a tv show, it should stand on it's own. There's also an atheistic and nihilistic streak throughout the show. Adams was an atheist, so this is unsurprising. The overall message I got was that it's all pointless.
Maybe a few more episodes could have filled in the gaps. As it stands, The Hitchhiker's Guide to the Galaxy is just a dreary disappointment.