This is a followup to @SorosFootSoldier@hexbear.net 's recent thread for completeness' sake.
I'll state an old classic that is seen as a genre defining game because it is: Myst. Yes, it redefined the genre... in ways I fucking hated and that the adventure game genre took decades to fully recover from. It was a pompous mess in its presentation and was the worst kind of "doing action does vague thing or nothing at all, where is your hint book" puzzle gameplay wrapped in graphical hype which ages pretty poorly as far as appeal qualities go.
So many adventure games tried to be Myst afterward that the sheer budgetary costs and redundancy of the also-rans crashed the adventure game genre for years.
What do you have against mind flayers?
Is it all the mind flaying? It's the mind flaying, isn't it.
I have the same issue with them that I had with prophecy-laden cults that hung out in sewers in 90s games.
Too. Much.
I know you're speaking of clichés in games, but the way it's phrases makes it sound like a real-world issue to you, which is funny to me.
Like as you arrive at your home you hear ominous chanting coming from the storm drain. You go to look and spot someone in the middle of summoning a demon, all you can think is "for fucks sake, we just had pest control stop by. I can't afford another drain-cleaning"
It kind of was with the millennium cults busting out regularly, like Heaven's Gate. But sewers were more for kids looking for ninja turtles.