Back then, when there was no internet (or it wasn't widespread), Sierra On-Line games were
vicious. Not only the wrong action meant instea-death, hope-you-have-a-savegame, but they were also sometimes impenetrable in an age where there weren't internet forums to ask for help. (There were hint books you had to buy, which in my mind were a scam).
For example, in Space Quest 2 there was a puzzle where some strange creatures tell you that in order for them to open a passage, you just had to "say the word". Keep in mind I was just learning English back then. The answer was you had to literally type "the word".