Space Quest 1 Plot Inconsistencies EGA version
When you broke the slot machine in the Ulence Flats bar, a message says that the Gippazoid Novelty Company would pay you back. Why would they pay you back something you've demolished?
The droid at Deltaur's weapons dispensary says
silly human, but Roger is dressed in a Sarien uniform and the guards aboard the ship recognizes him as a Sarien. But everybody knows the human race is always used in the Space Quest Universe to insult each other.
The address of the Gippazoid Novelty Company in SQ1 differs from the one written in the SQ2 Space Piston manual. A minor whoopsie. According to Scott Murphy,
Gippazoid simply got bigger and had to relocate for more office space..
Space Quest 1 Plot Inconsistencies VGA version
The planet Kerona is stated to have only one settlement, which is Ulence Flats (the Keronian underground city is obviously not a "known settlement"). However, when looking at the mountains in Ulence Flats, you're told about a place called Yomammy National Park (a spoof on the Yosemite National Park, which lies in close proximity to the former Sierra Oakhurst building).
The manual is messing up the meaning of the words: "sun", "galaxy" and "solar system". According to the manual, Earnon is a galaxy. But later on, it's made clear that the "sun" of Earnon is dying. AND, it describes Earnon as an "old system". The manual is actually talking about the "solar system" Earnon, which contains a planet called "Xenon". A galaxy contains billions of stars, not one.
A solar system, however, contains one star only. To put even more weight on this statement, the EGA manual says: "Far beyond the reaches of known space lies a planetary system known to its inhabitants as Earnon". Also, the word "sun" is the name of our star, which planet Earth is orbiting. The manual should have said "star".
The bar in Ulence Flats is called "The Oasis Bar" in the ega version (according to the coupons) and in the remake it's called "Rocket Bar".