I think there are common definitions that are often used.
The marketing definition: A game designed for people that plays video games as their primary source of entertainment.
The stereotype definition: A game featuring lots of violence, blood, gore and sex.
The gamer definition: A game of skill that is hard to master.
Honestly, the fact that people fight over this type of thing is just dumb..like most things on the randomness of the internets. I for one, can say “hardcore” games is a thing. But, even frickin’ Mario can be hardcore or Elmo’s world if you want it to. I don’t care about it because regardless, if the game is fun play it.
Umm… I think people will not agree with me…but the most ”hardcore” game I ever played is FFVII: Dirge of Cerberus..because of the enemies and bosses… I found myself being hardcore…and I found myself being frustrated.
To me, it means a game that you’ve got to get invested in. Like others have said, casual games are more “pick up and play”, while hardcore games take dedication and provide a good challenge. I would say games like Super Smash Bros are casual, while games like Demon’s Souls or ArmA 2 are more hardcore.
I think hardcore and casual are probably better player descriptions than they are game descriptions. You can play Mario in a casual way, or invest several hundred hours in it to get a perfect speed run.
A Hardcore game is one where it has something on the surface almost anyone can see but is MUCH MUCH more in depth when you go deeper into it. A good example is bunny hopping in FPS or Build orders and Micro Managing in RTS like Starcraft.