A person's death is discussed, though this is done more in depth in one of the bonus episodes. None in particular otherwise. The movie becomes intense, but more to make the person watching root for the people playing.
Overall:
The movie itself is a fascinating look into the Smash Community. While it is very long, it is quite worth it to watch. The movie does depict a large number of brand products and does advertise one specific game, being Super Smash Brothers Melee, heavily.