Casual gaming is real gaming. Theres no pretense in a game like Soduku.

i think what chrizum is getting at is that mainstream gamers are the casuals. the mainstream games are all the AAA hyped up and highly advertised games.

on the other end the more niche unadvertised off the beaten trail games are the more hardcore gamers prey.

Core market. They're the guys that buy your system every generation and buy every big title that releases.

The Casual market is strong right now but they're unreliable I think. I really don't see casual gamers buying a system every single generation and buying more then maybe a couple games each year. My parents for example bought a Wii this gen which is the first time they've bought a console since the PS2 in 2000; and while they like the Wii I don't see them rushing out to buy a Wii 2 when it comes out. I'm sure a lot of people will be in the same boat.

The casual market does not bring in more money, especially over time(Atleast not on Video game consoles.) Not only does their software bring in less revenue per game sold(they're generally priced at $50 or $40 to start, compared to $60) but the core market is mostly split between the PS3 and 360. If you add up the software sold by the two "Core" consoles they far outweigh the Wii. Just because the most successful company caters to the casual audience, doesn't mean it's the biggest market nor the most important. It was just the most ignored and thus had the biggest opportunity to be captured by a single company. The biggest software sellers for casual games (Wii sports and now Kinect Adventures), don't even bring in any revenue. They are bundled for free. Compare that to the Call of Duty games which probably sells 75% of their stock at full price ($60 in America). So not only is there more core games sold, but for every 5 full priced core games, 6 casual games have to be sold to match the revenue. Don't know how the pricing works around the rest of the world but I could imagine it's somewhat similar. The "core" consoles also cost much more money to purchase than the "casual" machine, thus bringing in even more revenue. 

Now that the competition for the "casual" market is heating up, the core market will become a goldmine for whoever caters to it the most in the coming years and coming generation. MS is being smart with their Kinect, especially short term, but i hope they don't forget about the core audience. Or else they will regret it when they all go back to the playstation brand. 

Your question doesn't even make sense.

"Core" refers to the people who make the majority of purchases on your console. It is a term referring to business, to the market. The "Core Market" is, essentially, the portion of the market that the company's products are primarily aimed at.

"Casual" refers to the way in which a person plays a game, although the gaming community has accidentally conflated it with "aiming for children, the elderly, etc". In reality, the most casual players of games are often those that play, for instance, Halo, or Call of Duty. The term "casual game" is a nonsensical term, as one can play any game casually, and almost any game in a devoted manner. (EDIT: Oops, I said "casual game" is a nonsensical term. What I meant to say was that a casual game is nothing more than a game designed primarily for the casual player - games that can be played in short bursts quite easily, as opposed to those that are designed to be played for hours at a time)

Most importantly, there's no such thing as a "Casual market". This concept has been invented by either the gaming media or the gaming community in order to pigeonhole the "lesser" games - essentially, it's a term created for elitist purposes.

If what you want to ask is whether games should be more complex, dark, realistic, and filled with guns and explosions, or more simple, light, artistic, and filled with rainbows and cute characters, then my answer has to be all of the above. A developer or publisher that limits their market or their target audience consistently will inevitably end up losing money as they find themselves stuck in a shrinking niche.

Core is obviously an abbreviation for Hardcore. In this context it is not used as you defined it. 

Also it's a lot easier to just call it casual than to describe it as simple, light, artistic, and filled with rainbows and cute characters every time. 

I do not think that you can separate the whole market in casual and hardcore.

I started gaming with the NES and subsequently purchased almost every console available. I own a PS3, a WII, a PSP and a DS and I still have most of my PS1 and PS2 games in my collection. For the last 2 years I have played and beaten around 25 games per year although I work 40 h per week. At the Moment I have like 17 games at home that I still have to beat. Some would consider me a hardcore gamer.

With the arrival of the trophy system and getting my first fulltime job I started to rethink my gaming habits due to time constraints. Against the new trends I have to admit that I totally hate online gaming, sandbox games, dialogue systems or moral systems, nonlinear games and I am not willing to invest more than 25-30 hours into a game, if it isn't a JRPG. .... after some heavy gaming disappointments l have now decided that I will  likely never buy an Activision, EA, Bethesda, Bioware, THQ or Take-2 Game again... In the end I simply could not enjoy Oblivion, Mass Effect 2, Dragon Age, InFamous, GTA 4 and refused to buy Fallout, New Vegas, Red Dead Redemption, War for Cybertron, Front Mission Evolved etc. I also have no interest in Egoshooters like COD, Killzone or Battlefield. For a hardcore gamer I would dislike almost all of the "big games" of the last 2-3 years. On the Wii I had a tough time with Wii Play, Wii Sports, Smash Brothers and Mario Kart, since I totally lost interest after the first hour. Those games are too shallow to keep me interested for a longer time. Even my wife couldn't enjoy the Wii... so we are clearly no "Casuals" also....

I do not seem to fit in either category. I am more like a  niche gamer. I choose my games according to its developer... I like Naughty Dog and Insomniac since PS1 days and grew up on Capcom and Konami since the good old Nes. My No1 Developer is still Square-Enix, and against the trend again I like their latests works more than the PS1 and SNES games... But I also like Katamari and the Lego games which are not so hardcore.... In the end it depends on the game. It has to be somehow complex and offer some depth, but it should not be too difficult and long at the same time...

I can't stand motion gaming so far and I am not at all excited for 3d gaming. I am about to sell my Wii because I hate the controller but somehow don't want to miss out some JRPGs like Dragon Quest X if it should arrive. I bought a DS because of some Square-Enix games and I don't like the Stylus and the Touch Screen that much... I don't like the 3DS having 3d, but the next Kingdom Hearts and a new resident evil will be on the 3DS... so I will probably buying it although I do not like the concept of it... just like with the Wii. Hmmm, maybe that is some sign of heavy hardcore fandom...

Mainstream/casual gamers also buy "hardcore" games. Most Call of Duty and GTA sales come from mainstream/casual gamers.

Hardcore is different again, though - it's an attitude, not a style of gaming or a market description. One can be a hardcore anything - there are hardcore Wii Sports players out there. And to be clear, I'm not saying that there are hardcore that play Wii Sports, I'm saying that there are people who are hardcore about Wii Sports.

And simple, light, artistic, and filled with rainbows and cute characters isn't consistent with the typical use of the word "casual", either. That's part of the problem. As used in this question, both words are being used poorly, describing completely different things (whether they're abbreviations or whatever), and the definitions are different depending on who you ask. To some, Mario Kart Wii is core. To others, it is casual - it's simple, light, artistic, and filled with cute characters, is it not? Pokemon also sits right there in that clear overlap.

The only words that are often used by the gaming community that consistently refer to opposing concepts are niche and mainstream. And there's really no doubt which of those are more important/desirable. By definition, the core market is important/desirable, but it must be noted that, when disruption occurs, the previous core market often weakens in favour of the new market that is opened up by the disruption. Casual and Marathon don't describe markets, they describe gameplay styles, and thus both are equally important and desirable - indeed, they work quite well as a complementary pair, with many people wanting both types of game, to suit varying moods. And hardcore have always been niche, they don't matter.

I don't think just because a game involves violence and shooting that it isn't bought by the casual user.  I define a casual user as someone who doesn't read gaming sites all the time, buys and plays games occaisionally. Halo, Modern Warfare and other big sellers are pushed into huge sales because of these casual users.