Mass Effect 3 has been rated as a 15 in the UK; the BBFC cites strong language and occasional strong violence as their reason behind the rating. This is in the face of rumours that led some to believe it might be an 18, a move that would have meant anybody under that age would be unable to purchase it without the aid of an 'adult.'
The 15 rating brings it in line with Mass Effect 2 – that was given a 15 for strong language and moderate violence, to give you some indication of what to expect from the last in the trilogy – which was given a higher rating than the original game's 12.
The BBFC has also rated 1 hour and 22 minutes worth of cutscenes as opposed to the 23 minutes submitted for Mass Effect 2. This would lead us to believe that there's not only a little more non-interactive plot development, but that there could be quite a few different versions of the same cutscene, depending on your choices up to this point.
Mass Effect 3 will be available in March.