SAO is the more child friendly story. Kirito and his friends and even his enemy in the fantasy world Aincrad are all lovable with good intentions. The action is clean of blood and gore, there are cute awkward moments (the night Kirito and Asuna spend together and they have different ideas as to what it means) and it has an overall sweet and innocent tone. Now for the however, the story jumps without really showing the nitty gritty progression throughout the game, we see very few boss fights and because of that it feels like this is more of a side story. Maybe the creators were limited on funds and how many episodes they could produce and decided not to show each floor being cleared since that would’ve doubled the amount of episodes. Another thing is how it tries to be in two anime genres. The boys adventure and action is directly aimed for the fans of shonen while the romances and quirky embarrassing moments (Silica is so concerned about what her skirt is covering and Kirito not looking while she is fighting a monster is silly funny) is more shojo. Overall it deserves its PG rating.
Btoom is defiantly not for children and must’ve been created for male adults (the boobs are larger than life). Instead of being inside a virtual world the characters are stranded on an island and must kill each other with bombs. Sakamoto, when we’re first introduced to him comes across as a pathetic creep (22 yr old, unemployed, living at home, plays games all day, is married inside of the game and has a violent temper) but once on the island he is strangely noble and kind of attractive which is jarring to how he is RL. The blood and gore is plenty, so is the betrayal and the rape. Watching this, I felt fear and very dirty because of this; teenage girls are brutally raped (we don’t see it happen but there is the lead up and the after math and the screaming) and there is Sakamoto’s relationship with a fifteen year old that begins to turn sexual. The series is fast pace and obviously not shying away from showing everything and knows exactly who they want as an audience. The rating is iron stomach friendly.
The verdict: SAO is good fun and makes me want to play video games. Btoom is scary and I don’t want to go to the island. I enjoyed both but if you are easily disturbed don’t watch Btoom.