English Dictionary

underworld

noun

(mythology) The world of the dead, located underneath the world of the living; the afterlife. / That part of society that is engaged in crime or vice.

Hades is the ruler of the underworld in Greek mythology.

意味（1）

(mythology) The world of the dead, located underneath the world of the living; the afterlife.

意味（2）

That part of society that is engaged in crime or vice.

意味（3）

(video games) The portion of a game that is set below ground.

In the underworld theme, low notes create a darker feeling that matches the cave setting. This song also creates a sense of continuity across early Mario games, since it's a remix of SMB1's original underworld theme.