This is why all these distinctions and rules and labels begin to break down for me. The moment I can find an exploit, I'm going to rip the definition asunder, because it's an inch away from being a slippery slope.
The purest and most basic group you can put these in is "games." Period. To sit there and try and drum up a set of arbitrary criteria to further segment them into what we are "supposed" to play versus not is hugely pompous.
I've heard it be the "hardcore versus casual" thing for a long time, but when I try to get further clarification, it falls apart. You can take any of these so-called designations and completely dismantle them. For example, what constitutes hardcore?
"A harsh learning curve." Really. I'd call Ikaruga hardcore and it takes all of 30 seconds to learn the controls. Hell, so does Pacman, Pong, Tempest, Super Mario Bros, Tetris...
"Competition." Again, Madden, by all accounts, is not hardcore. It's just that 8 million people buy it year after year. That kind of mainstream penetration almost guarantees it is not "hardcore." And there are oodles of people playing it off and online in competition. Beyond that, the only games that might also fit here are fighters and shooters. You can't compete in RPGs that directly or easily.
"Has to be difficult." I think the last honest bastion of truly difficult games are bullet hell shooters, and those are appreciated by a fraction of a fraction of a fraction of the entire population, who also happen to be entirely sadomasochistic. Most games that are hard these days rely on cheating AI - racers with invisible rubber bands, fighters where characters do more damage/move faster/perform moves that are impossible to perform based on the last input, shooters were you just get swarmed by enemies, etc etc. Twitch gaming might be the only "true" games that are difficult because they are based entirely on skill, where other games force players to compete against odds on top of the current situation.
"Takes a long time to play." So does Monopoly. Next.
"Has to have awesome graphics/physics engine/some other piece of graphics whore/eye candy/engine junky bullsh*t." Zork, mofos. Nethack. Again, all the early twitch games. Certain RPGs.
"Has to have a definite end." NONE of the early twitch games did.
"Has to feel like you've accomplished something." It's a game, people. You aren't building a porch.
And so on, so on.
I think the better way to explain it is that gamers are shallow people and want to feel good about themselves, and the way they measure this is to look at the games that look like they forced the developer to work the hardest. So when you hear about the latest 360 game, you get a bunch of nonsense about what resolution it runs at, how many polygons are on screen, what sound codecs are being used, etc. And then you learn about the advanced AI with all these fancy terms. You hear that lots of stuff was motion captured, that developers went the "extra mile" for certain things (such as consulting a general for a military game and truth-to-reality, or modeling tracks in real life for a racing game), etc etc etc.
So when Joe Gamer looks at Gears of War, he thinks the graphics are awesome, the monsters look cool, it's bloody, there are big guns, fancy sounding words to describe everything, bla bla. And he feels good because all of a sudden he starts thinking "Hey, these guys care so much about my entertainment that they went through all this trouble."
Then he looks over at Brain Age and calls it stupid because the graphics look so simple. Truly, it looks like Nintendo copy and pasted stuff from a "55,000 Clip Art Super Deluxe Package" program and then added a scoreboard.
I think that is what it's come down to - production values. Nevermind that no one had envisioned a game like Brain Age before it came out, or a userfriendly interface in Wii Sports that actually worked, because it doesn't matter. The games look like tech demos and that's all this entire industry can latch onto and debate endlessly, instead of seeing it as another method toward entertainment on a console. Suddenly it's bad to want to play things like Bejeweled and Cooking Mama because they are simple looking with simple rules.
I think that is how gamers do it - they try to find what makes them feel like they are special to have groups of people around the world slave away in tiny offices to deliver what is supposedly a great gaming experience. The great thing about this perspective is that it's constantly moving forward, so what is considered "hardcore" today won't be that next year. Gears of War will be forgotten about the moment its sequel hits, or when something even more graphically intense drops along.
So I don't think we can break down the definition, because it's always changing and evolving, and even then it is pretty much bullsh*t anyway. You can be hardcore in Animal Crossing, Picross, and Madden just as much as you can be in Smash Bros, Halo, and Metal Gear Solid. Getting 999,999 bells is just as much fun to certain people as getting a brain age of 20 or slaughtering a bunch of Locusts.
I don't see why it can't just be games anymore, like it used to be.