Space Quest: The Sarien Encounter was an early text command adventure game developed by Sierra, and was very similar to King's Quest. Space Quest took a more humorous approach to the adventure genre than the more serious King's Quest series. Most of the settings and characters were outright parodies of famous science fiction franchises like Star Wars, Star Trek, and Alien. The Sarien Encounter was the first in the Space Quest series, which would eventually have six installments. It also introduced the character of Roger Wilco, a bumbling janitor from the planet Xenon who somehow keeps managing to save the galaxy. The Sarien Encounter would see a remake in 1991, which featured improved graphics and a more user-friendly point-and-click interface for the gameplay.
As the game begins, the scientific spaceship Arcada is attacked by the Sariens, who are after the experimental Star Generator. Roger Wilco is napping in a broom closet during the attack, and emerges to find the ship overrun and his crew mates slaughtered. The Star Generator has been stolen from the Arcada, and the ship is heading for destruction. Roger manages to get to an escape pod and crash onto to surface of the planet of Kerona.
Kerona is a desert wasteland, and Roger has to make it across the sandy wastes to find protection. Beasts lie beneath the sand waiting for passerby to devour, so Roger can only go so far. He instead must navigate a series of tunnels filled with deadly traps and creatures. Other hazards include a Sarien spider droid sent to terminate him and a violent beast known as Orat. A holographic image tasks Roger with the job of killing Orat. Players have a few options to carry out this mission: they can lure the Spider Droid into Orat's cave where they destroy each other; or they can also hide behind some rocks that Orat can't navigate past and toss a fire extinguisher at Orat, who explodes when he eats the object. Regardless of the method used to kill Orat, Roger takes a piece of Orat. The Orat piece is exchanged for a skimmer that Roger uses to get past the sand worm creatures and reach the town of Ulence Flats.
When Roger reaches Ulence Flats, he sells the skimmer for 30 buckazoids and a jetpack. Ulenece Flats happens to have a used starship lot, but Roger doesn't have near enough cash for a ship or a navigation droid. The only source of income is the slot machine located in the town's bar. The problem with the slot machine is that three skulls will result in Roger's disintegration. Roger somehow manages to survive long enough to clean the machine out, which gives him enough cash to get off the planet. While in the bar, he overhears the coordinates of the Deltaur, the same ship that destroyed the Arcadia. Roger buys himself an appropriate ship and droid, and takes off in pursuit of the Sariens.
The ship arrives at the Deltaur, and Roger uses his jetpack to reach the ship and break inside. He arrives inside a laundry room, with Sariens approaching. He hides inside the washing machine, gets put on the spin cycle, and somehow comes out inside a Sarien uniform. The disguise allows Roger to acquire some weapons, which come in handy because he trips getting out of an elevator and loses his helmet. Roger battles his way through the Deltaur until he comes across the Star Generator. The Sariens have installed it into their ship and plan to use its power against Xenon. Roger enters a self-destruct code and escapes from the ship in time to see the Deltaur explode. The people of Xenon celebrate and award Roger a golden mop in gratitude.
Space Quest was a text-based adventure with a graphical presentation. Players guided Roger around the world with the arrow keys, but had to type in commands to interact with the world. These commands were used to look around, gather objects, talk to characters, etc. Items were collected and then used later to solve the puzzles and obstacles presented to the player. Quick thinking and typing were often needed to survive. It was helpful to occasionally enter commands prior to needing them and then recall said command with the F3 key. One such situation was when players had to blast their way past the Sariens in the Deltaur. The section with the skimmer also required that the player navigate the desert landscape while avoiding rocks that would cause the skimmer to explode. The slot machine sequence also served as a diversion from the main gameplay, as players had to rely on luck and save often in case of disintegration.
Besides the manual and a couple of advertising booklets on Siera and AOL products the Space Quest I box also came with two coupons that referenced occurances in the game.