Some of the characteristics that mark Christopher Marlowe's Dr. Faustus as a Renaissance tragedy are the questions addressed, comedic relief and the death of the hero. Christopher Marlowe lived from 1564, the same year of birth as William Shakespeare, until his mysterious death in 1593.
In the tradition of dramatic tragedy, the questions that are addressed in the play are the grand and large questions of life, such as: What is the meaning of life? Why are humans here? What does life mean if it only always ends in death? Is there god(s)? How is the will of a god to be known? In Dr. Faustus, these large questions are addressed in the form of Faustus's unquenchable thirst for knowledge, a thirst that leads him to barter his life with the Devil; Faustus's doubts and regrets about his choices; Faustus's final demise, which was a terrifying end and death.
In Greek tragedy, narrative elements were presented by the Chorus who moved the plot along and gave explanations. In Renaissance tragedy the Chorus is replaced by clowns and fools: Clowns are rural simpletons who give information that moves the story along and who utter unintentional plays on words: their language is witty and amusing but it is accidental, coming about through ignorance of the English language. On the other hand, fools are urban city dwellers who fill the same story/plot function but who are witty and amusing by intention because they have the intelligence and education to play with words by design. In Dr. Faustus, Marlowe combines these two traditions by having Choruses and clowns, Rafe and Robin, who give story information to move the plot and who are witty and amusing (it is possible that they should be considered fools instead of clowns, but they are generally referred to as clowns).
In Greek tragedy, the hero does not have to die. Renaissance tragedy changes this and requires that the hero of a tragedy must die as justice for his wrong doing, well known examples are King Lear and Hamlet. Marlowe constructs Dr. Faustus according to the Renaissance model and has his tragic hero, Dr, Faustus, die horribly in the end.
This change in the form of Renaissance tragedies demonstrates a change in the idea of "catharsis." For Aristotle, a tragedy had catharsis because the internal action of the play was worked out to a satisfactory resolution giving the audience a happy ending in one way or another, such as exile instead of death. In Renaissance tragedy, catharsis came to mean the audience could feel that they had experienced the tragedy with the hero and were relieved of those wrong urges and feelings in themselves. In other words, the focus of catharsis shifted from the play, for Aristotelian Greek tragedies, to the audience, for Renaissance tragedies.
For more information on Aristotelian ideas of Greek tragedy, see Professor Larry Brown's explanations.