The key concept is immersion, one of the most debated things in game studies, making the volume a very important contribution. Examination takes place from many perspectives and on many subjects, ranging from psychology experiments to extreme role-playing and reality television - the last of which has, surprisingly, been tied really well with the game studies content, through analyzing its visible game-components. A big plus goes to the editors for that, and for the fact that Torner himself has in his own article (which I thought the best of the book) built an exemplary bridge between the two subjects, one I hope gets both cited and emulated in the future.
The essays present various important points, with varying thoroughness. Some might just as well have come out in academic journals, others are more like openings than thorough research, but they too have their function in the mix. Even the ones I had problems with, due to lack of in my opinion mandatory references (Writing on Nazi representation in games without citing Frasca, 2000? Or on casual games without Juul, 2010?), I will probably cite a lot. I also hope that the authors will produce more - I can for example see a lot of potential in Fuist's work on self-improvement through tabletop combining with that of, say, Meriläinen. (I personally lament the fact that I did not have access to Newsom's data before I submitted my dissertation the most.) And the fact is that while I may think articles with just 10 references may be somewhat shallow on one side, the findings themselves can nevertheless be very impressive. In addition, the shared bibliography at the end is quite remarkable, and is something especially inexperienced role-playing scholars should pay a lot of attention to, when they think about making off-handed remarks about immersion, bleed, game presence, or so forth.
All in all, a solid book, an approachable book, and a good academic contribution to the study of immersion. Were I an outsider reviewing it, I'd probably give it four stars out of five, with some harsh words on the references of a couple of authors and a lot of praise for the clever audacity of certain others. As one of the authors themselves, however, I settle for saying "I like this, and I'm proud to be included in such fine company".