When clicking the "smell" icon on the left plant outside Software Excess store, the game message is "This plant was provided courtesy of Shapier Florists" - referring to Quest for Glory II: Trial by Fire (1990). The correct spelling is "Shapeir".
One of the games in the bargain bin at "Software Excess" store is called "King's Quest XXXXVIII". The proper Roman numeral of the number 48 should be XLVIII.
In the CD-Rom version of Space Quest IV, there is a point bell glitch which is unable to trigger in which Roger Wilco changes back into his space uniform. The player was supposed to get 3 points in order to get 315 out of 315. But due to this glitch in the game, the player will end up with 312 out of 315 points total. Unless the player gets the unstable ordinance and keeps it allowing the player to get 332 out of 315 points.
When Zondra drops her credit card at the Mall. Roger Wilco claims it and uses it to withdraw money. But Roger never meets up with Zondra and her friends and is unable to return her credit card. It's unknown if Roger ever returns her credit card as she is never seen again in Space Quest V and Space Quest VI.
Although this game covers the Space Quest sequels up to 12. Only 8 out of the 12 Space Quest games are playable, Space Quest 1, 2, 3, 4, 5, 6, 10, 12. Two of the Sequels including Space Quest V 1993, Space Quest 6 1995. There are 4 Space Quest games missing which were never shown that are unplayable. Space Quest 7 which was officially cancelled, Space Quest 8, Space Quest 9, Space Quest 11 was never made by Sierra Online.