Games that are uncompromising with its design are hardcore. The designer is usually king. You have to follow the system (rules, etc.). You'll either love it or hate it. But the designer do not care. You take it or leave it. Rarely these games sell because of its uncompromising nature, and rarely do big publishers take them.
Example games:
* Alien Soldier (MD)
* Umihara Kawase(SFC)
Casual games, on the other hand, are toned down to please everyone. The system is simplified to provide quick gratification. Usually, marketing has a big say on this.
However, casual games and hardcore games are not a dichotomy. If it's not casual, it doesn't mean its hardcore, or vice versa. You can play a hardcore game quickly. You can play casual games long.
Proud member of the Sonic Support Squad.
@ChronotriggerJM
Like I said, you can play casual games long. But the gratification is quick. Your example, Smash Brothers, exemplify it (quick round matches). Wii Sports, too. My mom and I spend long hours with it.
That's the "casual" in casual games. That's why RPGs aren't casual (but they aren't necessarily hardcore, either).
Hardcore games have a niche feeling in them. And while the facade may look "casual" (as in cute), it can be hardcore.
Proud member of the Sonic Support Squad.
Pokemon is definitely not casual (gratification is delayed). But I'm not sure with being hardcore. Nintendo has come up with a winning formula (one that generated several sequels), and I doubt that the designers have any problem with marketing. (I think they are in concert because marketing can have several toys out).
It's not the difficulty per se that makes a game hardcore. It's the uncompromising nature of the designer. Usually if you pick up a hardcore game, there's a bit of resistance on your part because the designer had a different vision on how to do things. But if you persevere, you may come to appreciate the game. Or maybe hate it even more.
Pokemon, is an OC game, just like Monster Hunter. It sucks you in and you can't let go (just one more monster, one more hunt, one more item). It has a certain formula, the urge to collect.
IMO, Pokemon is neither hardcore nor casual.
Proud member of the Sonic Support Squad.