What is a “Middle Game”?

What are the requirements for the game to enter this list?

I have a game that could fit in here! Can you add it?

Why did you make this list?

A bunch of these games make millions in gross revenue! Does that mean if I make clones of these I’ll make a ton of money too?

Isn’t there a lot of survivorship bias involved with taking only the “successful” middle games?

How did you figure out X data about the game?

What are some other games that more or less fit but you didn’t add for various reasons?