I watched this last night, and stayed up until 5:00 AM, getting a meager 2 hours of sleep. Yeah, that was a really bad move, but anyways... so good, so addicting. I'll be honest, I'm not one to normally have feels, but one of the episodes really got to me. Probably one of the best anime I've watched in a while. Tackles some serious mature subject matter while putting it into the context of a life-or-death MMO. The episodes are only like 23 minutes a pop, and yet the individual story arcs can get you seriously emotionally invested in 1-shot characters because the show moves at such a fast pace. The first 15 episodes are like half story arc half filler, and yet the "filler" episodes are in a way the best part because they tackle serious human issues in a self-contained way. My only complaint so far with it (I was at episode 18 or 19) is that it a tad too "anime". "Fan service" is just annoying to me, which is a pain in the ass because if I have to look away from the screen I can't read the subs, and sometimes the "assets" are right next to or behind the subs. Call me prudish if you must, but I don't want to look at 14-16 year old animated butts or breasts. And wow, I got more involved in this post than I thought I would. Anyways, yeah. It is pretty good. Give it a go.