To start off, I just want to say I'm willing to excuse a lot. I intentionally went into this wanting to watch a show that wouldn't challenge me. I wanted something dumb, where I could turn off my brain and have a good time.
That being said, Btooom is awful. I used to think being boring was the worst crime entertainment could commit, but I know better now. A show can be so bad that it can have a negative effect on you. It goes beyond being boring, and is painful to watch.
I can handwave that somehow the bags are intact after their wearer has been killed. I can ignore how close the characters get to the explosions and somehow manage to get away unscathed, without so much as a ringing in their ears. I can suspend my disbelief and accept that they have the technology to build bombs that just vaporize a certain area, and that the company could afford all of this stuff. I don't even need an explanation about the organization or the spectators. We all know why they're watching, they're watching for the same reason we are. They want to see some bad ass fights. They want to see the innocent become corrupt. The Man of Tai Chi was a pretty terrible movie, but its message dealt with our desire to see such things, and it did it pretty well.
In fact, I wouldn't even mind no explanation at all as to why it's happening, that there was just a chain letter, and people are sent off to this island and nobody knows why. It's not necessary.
I can even overlook the fact that none of these bombs work the way they would in the real world, and that the damage they do at different ranges is completely inconsistent.
But I can only overlook these things if there are some other merits to the show that make it worth it. As it is, they only make all of the failings of this show just that much worse. Honestly I didn't care about any of those problems, because they're rather nitpicky for a setting like this which is already ridiculous, just as long as I got what I came for.
However, Btooom! didn't give me what I came for. You'd expect out of a dumb action anime that there would be some sweet action, right? Especially for this setting. A shut-in who does nothing but play one game all day is tossed into a real life version of the game. Here, he would be a god amongst the rest of the "players". Yeah, cliched and uninspired, but it works. Except it doesn't work if you don't do that.
Somehow, after the protagonist Sakamoto instinctively throws away a box that is counting down and it explodes, he fails to realize that his bombs explode after he activates them and they count down to zero. SERIOUSLY? Are you kidding me?! Anyone who is literate enough to understand that it's counting down should have instantly understood what was going on after that first experience. I honestly can't comprehend why they had to have him figure out what was going on at a later point. Was it because they didn't think the audience would understand? If so, they're insulting the intelligence of their audience to an extreme degree. And if not, they're saying that Sakamoto is an idiot. This may be a small grievance, but it will set the pace for the rest of the series.
There is only one time in the whole series that Sakamoto does something truly clever, with Oda and the trap bombs. And there is only one time he does something in utilizing the game mechanics in the fight between him and Kira with the sonar, however, how he actually did it wasn't even properly explained. I can guess at how, but it would only be a guess.
You'd think every fight would be a showcase of Sakamoto, "The Strongest Player", outsmarting his opponent with some grand scheme that might not even make that much sense, but everyone would be shocked at how his knowledge of the game's mechanics and tactics had allowed him to create an incredible masterplan. Not exactly the most original kind of storytelling, but still fun regardless. I wanted to see how the tactics of the game worked or how they did or didn't translate to real life, and how someone could use bombs in more interesting ways than just throwing them at each other.
Instead, Sakamoto beats almost everyone by just tossing a bomb at them. His methods of survival are mostly running away and barely dodging explosions that should have killed him. However, most of the show ignores the action to focus on the characters and their interactions. This might have been really interesting, to see people break down as they face life or death situations. Or, it would have been, if the characters or their interactions had been done with any finesse or done well at all. This leads me to the worst element of the entire show:
What is unforgivable is how the show treats the main female character, Himiko. It's god awful. SAO had the problem where they had to nerf the supposedly badass lead female because the protagonist had to be the greatest ever, but even they managed to make her able to do something. Here, because the "best Btooom! player in Japan" is hardly able to do anything, in order for him to seem cool in comparison they have to make sure that she is completely helpless in every scene she's in.
She's a Btooom! player as well, she should be able to use these tactics to her advantage. She should be better than most everyone on the island. The worst part is that the show, in part, agrees. She's shown to have killed around 4 people before meeting up with Sakamoto. She uses a game tactic to draw him right to her. She should be fully capable to take on just about anyone on the island except for Sakamoto. Yet she is completely paralyzed any time it comes where she should be able to work something out herself, and always waits for someone to bail her out.
She could have been an awesome character, on par with Sakamoto's skill, but they chose to make her weak despite it. Not that being on par with Sakamoto would mean much with the way the show portrays him anyway.
This is ignoring all of the nasty stuff relating to how she thinks about herself, and how her only motivation to stay alive is Sakamoto. I've got no problem with rape in stories, as long as there's a good payoff. Btooom! didn't earn it. They even used it for the purpose of fanservice, which is pretty disgusting. In the end, its inclusion was just obscene.
The one time she actually works towards her potential, she makes a fairly obvious observation about the homing BIMs, but somehow doesn't realize that the person using them would just select her as the target next. There were plenty of opportunities where she could have used her knowledge of the game to do something awesome, especially when Date had cornered her, and she thought Sakamoto was dead. At that point you'd imagine that she'd want revenge and utilize some tactic from the game to pull off a crazy move and win the fight.
Speaking of characters, about 3/4ths of the way through the series when Sakamoto has teamed up with his group and is starting to meet other strong and more interesting players, things appear to get interesting. Finally I thought I might get to see some interesting fights. Unfortunately that doesn't happen. The most interesting characters in the show, who weren't that interesting to begin with, get only one moment to shine each and they don't even complete their character arc within that time. For the most part, these characters are alive by the end of the show, and a lot of mystery surrounds them, what they're going to do, and where they're going to end up. I'd expect a satisfying conclusion to each of these enemy paths, but that never happens even though there's 12 whole episodes and about 3 of these important characters. It doesn't help that things really start coming to a head in the last stretch of the show with no real climax or progression between any of them. This means that the first three quarters of the show are unreasonably slow.
The characterization of Taira bothered me, if only for the inclusion of one scene at the end where Sakamoto grieves for him. He mentioned how he would miss his little quirks of eating not quite cooked instant ramen and telling stupid jokes. I liked the fact that he didn't wait until the ramen was fully cooked. It was a quick, unobtrusive, and subtle way to flesh out his character and make him seem like a real person. However, he never said any of those jokes that Sakamoto mentioned during the show. Something like that would have made his character more unique and would have made his death and the subsequent scene more powerful.
My last problem with the show is whatever grotesque version of what they consider to be moralizing.
I'm sorry, if someone has killed people before, and is trying to kill you unprovoked, they have lost their right to live. This is ignoring the blatant truth that leaving them alive is incredibly dangerous in the long run, which the show acknowledges. Showing mercy to the kid was understandable, since they didn't understand what a monster he really was, but Sakamoto acting like he was taking a moral high ground by not killing people who had killed others, were going to kill more people, and were trying to kill him, was infuriating. Killing the innocent and killing the guilty are obviously different.
A quick note about the technical aspects. The animation wasn't anything special, but for some bizarre reason that I see happen now and then in shows, when the show cuts to someone's feet walking the framerate drops to a nauseatingly low level. The sound wasn't particularly bad, and the opening theme was pretty kickass, probably one of the best parts of the show.
Despite all of these grievances I've listed, even the unbelievably poor treatment of the female lead, I would have had a great time with this show if it had smarter action scenes. That's literally all I asked for, and they didn't even give me that.
It squandered what little potential it had. I couldn't like it even though I wanted to. It's offensively bad. Honestly, it's one of the worst shows I've ever watched. So it doesn't work as an action show, it doesn't work as power fantasy, it doesn't work as a drama, it doesn't work as a romance. So what does it have going for it? Nothing.