The post “Relax!” talks about relaxation, agreeing with Bogost that casual games seem geared towards providing relaxation. However, I think that in some ways more hardcore games can be relaxing as well. For example, Team Fortress 2 is a game that I would consider as more of a hardcore sort of game rather than casual, though it has some aspects of casual games such as interruptibility. When I play Team Fortress 2, most of the time it is pretty laidback and relaxing. Once I find a nice server to play on I can zone out and play for hours without realizing it. I also think that games like Dark Souls can be relaxing as well, despite the difficulty of the game. Dying and having to run the same gauntlet again can become methodical and second nature, and I think with more experience in the game it becomes easier to play in a relaxed state. I always just take my deaths in stride, since anything lost in death can be regained, so it is not as stressful as as it seems like it could be at first.
Of course it is also possible to become frustrated in either of these games due to not making progress after repeated attempts, but that is also possible in more casual games as well. I think the key difference is that hardcore games are often harder than casual games, so the player needs to be in the right mindset to be able to relax with hardcore games. If the player is not one to get frustrated with failure then I believe that hardcore games are viable sources of relaxation.