You fight your way out of the underworld, die, and do it again, which is weirdly more fun than it sounds.
Fun fact: First video game to win a Hugo Award, a prize normally reserved for science fiction literature.
Came out in 2001 and competitive players still treat it like it's the only game that exists.
Fun fact: Was developed in just 13 months, yet its competitive scene has thrived for over two decades.