Space Quest is rated the maximum "Cruel" under this system, as it's easy to render the game unwinnable with no feedback that you're in this state. Almost all modern adventure games are less cruel.
I’m looking at you KQ5 - “Failing to rescue this rat will result in yet another DMW. This is probably the single most infamous puzzle in King's Quest 5”
https://www.ifwiki.org/Cruelty_scale
Space Quest is rated the maximum "Cruel" under this system, as it's easy to render the game unwinnable with no feedback that you're in this state. Almost all modern adventure games are less cruel.