A little late to the party, but...
Hardcore applies to gamers where the buyer wants a specific product. It doesn't matter how good, or unique, or complex the game happens to be; the key factor is that the customer watches the trailers online, pre-orders, and pays $60.
Casual gamers play something to pass the time. They don't really care what game they are playing as long as it isn't overly involved or boring. When given the choice between two games with a high price disparity, they will buy the cheaper game.
Casual gamers are great because the population is greater and they require a lower up-front investment. On the other hand, the profit margins are lower and chance of significant sales tends to be low.