Here: Spending time at a game doesn't make you HARDCORE. Each of the games I selected demonstrates several factors of what constitutes a hardcore game: difficult, exclusive, and ultimately clever mechanics that reward those who face up to the challenge. Their brilliance isn't immediately accessible, and they're games so completely entrenched in the conventions of their genre that they've become virtually opaque to most casual gamers. You're HARDCORE when you understand a gaming genre so thoroughly that the opacity doesn't exist; that design aspects that might prove cumbersome or unfriendly to outsiders seem utterly natural to you. HARDCORE games cater to those who have simply played so many games from a given genre that they've become oblivious to any possible hurdles to entry; HARDCORE games have deep and evolved mechanics unencumbered by the need for accessibility.
Dodanpachi Daioujou is a shooter for the bullet pattern fiend. If you don't like mesemerizing waves of bullets and pattern-based scoring mechanics wed to an exceptionally high reflex requirement, the game's appeal is inscrutable to you. I have friends who consider themselves 2D shmup fans who find the game too unforgiving, but the game has a very rabid fanbase among folks who are considered "hardcore" within the genre, myself included.
Umihara Kawase is a clever, physics-based platformer that's available on in Japan. It's a difficult, tricky game with an obscenely large number of platforming puzzles and secrets. If you want to play it, you'll have to import it for the SNES -- which qualifies the game as particularly "hardcore" for modern Western audiences. But if you're a 2D platforming fan, it's so worth it.
Alpha Centauri is the purest form of the 4x, right down to unfathomably abstract tech trees, heavy-duty terraforming exercises, and an uncompromising AI. Not only do you have to love navigating loads of menus for a tiny piece of numerical data, you have to be able to process the vast amount of contextual information that accompanies it. It's a fundamentally daunting game, loved by bearded gamer types and loathed by those to whom it appears as an Excel spreadsheet with little tanks and cities haphazardly placed within it.
Animal Crossing isn't hardcore: there're no barriers to entry. It's simple and stupid -- literally. It has no challenge save the limits of your need to pointlessly collect items. There are no failure conditions. It's just an idle waste of time that demands no real mental energy or reflex skill to participate in save the ability to navigate an ugly weeble dude around a virtual city full of repetitive weeble animals. It's a sort of crude social simulator that creates a quasi-immersive, non-threatening alternate reality, and it's eminently grokkable by ANYONE.
