Metal Gear Solid: Ground Zeroes has received an ‘M’ rating, which shouldn’t really come as a surprise.
The rating on the ESRB website says that the game contains ‘Blood and Gore, Intense Violence, Sexual Violence, Strong Language’. A more detailed description says that ‘This is an action game in which players assume the role of an elite soldier through military missions in Cuba. Players infiltrate various bases and use pistols, machine guns, and rocket launchers to kill enemy soldiers. Firefights are highlighted by realistic gunfire, slow-motion effects, and large blood-splatter effects. Players can also employ stealth attacks (e.g., choking, knife stabbing from behind) and have the ability kill non-adversary characters/prisoners.
One cutscene includes a depiction of blood and gore (e.g., a character’s intestines exposed during a dramatic procedure to remove an object). The game includes an audio file in which a female character is sexually assaulted by male characters; while there is no visual depiction, sounds of ripped clothing and struggle can be heard. The words “f**k” and “sh*t” are heard in the dialogue.
The final sentence in that description is probably what Hideo Kojima was referring to when he said that the game would cover controversial and taboo subjects. Context is very important but it is almost guaranteed someone will make a big deal over it. MGS: Ground Zeroes launches on PlayStation 4, PlayStation 3, Xbox One and Xbox 360 in March 2014.