Story: 8/10
Like I said, I'm biased towards this anime's story; I love the plots where humans are pitted against each other in a twisted game that tests their desire to survive as well as their sanity. I feel like this setup, while becoming less and less original, is a great storyline for a horror/psychological anime.
Art: 9/10
There's no doubt that Btooom! is extremely well animated. Each of the character's designs fits their personalities, from the cute child psycho to the relatively ordinary NEET protagonist with a big heart. The only problem I had was sometimes the body-to-face proportions looked a little strange to me, mostly with Himiko. Her head was kind of a weird shape, but that could just be me. Either way, it's nothing to complain about.
Sound: 8/10
There isn't too much to say here. I really loved the OP (up until the last episode, where it was changed), and never really listened to the ED. The voice actors did a good job, and you could start to see in their voices when their mental state began to deteriorate.
Character: 9/10
This is where I think Btooom! really excels. I think all of the characters were likable or detestable, as needed, in their own way. My personal favorite would be Kira, who I think had a great background and was extremely disappointed when he didn't get more appearances later on in the anime. Even though he's a deranged sociopath, he still has that intrigue about him that makes you want to know more about him. I think when an anime makes a few of the "villains" likeable, they've done an excellent job of crafting their characters.
Himiko was a bit annoying at first; she seemed to exist simply for Ryouta to save. However, her back story (while not original in the least) was believeable and she started to redeem herself towards the very end. Speaking of Ryouta, I think he was a fantastic protagonist -- he wasn't wimpy, but he also wasn't a brutal killing machine. He had a sense of morals, but he wasn't like "NO I CAN NEVER KILL AT ALL!" which can be annoying in these kind of stories. Of course, the way he always managed to dodge BIMs simply because he was the main character was aggravating, but that doesn't really have anything to do with his character.
Enjoyment: 9/10
Btooom! is definitely worth watching simply for the enjoyment factor. No, it may not have an incredibly complex plot or huge mindfucks, but if you were to watch this anime after it had finished airing, it would be the kind of anime that you marathon. It's action-packed plot and interesting characters make each episode go by quickly, so even if you don't enjoy it, it should be a quick watch and is at least worth a chance.
Overall: 7/10
Based on my ratings for other factors, I should be giving this anime an 8 or 9. However, I have to give it a 7 simply for the ending. Throughout the second half of Btooom!, the focus shifted slightly to a romantic one. There was still action, but more of the time was spent with Ryouta and Himiko's relationship than badass bomb fighting. The ending was extremely disappointing in the fact that it had more focus on romance and wasn't really any unexpected twists at all; although based on the ending, I think there is high hope for a second season.
Overall, Btooom! is a great watch if you're looking for a survival anime with a world that sucks you in and keeps you on the edge of your seat, even if it is a little predictable at times.
