What is the non-funny equivalent of a spoof? Such as a dark, gritty, alternative re-telling of a story

I'm wondering if there is a word for a non-funny spoof/parody, as described in the title.

Without giving away any spoilers, Invincible (the TV series, haven't read the comics) seems very much like an alternative reality/mashup of classic super heros (the parallels are obvious, Superman, Gambit, Flash, Batman etc) but told in a very dark way.

Like a dark homage?

A word that might fit is to call such a work a reimagining. A reimagining of a work takes existing elements like characters, setting, genre, tropes, or plot, and changes them in some way. It doesn't necessarily indicate that the new work is darker or grittier or not comical, but a reimagined work will often differ in key aspects like plot or tone. Typically, a reimagining will subvert certain elements of the original work in some way.

In the example you mention, the work could be described as a reimagining of common superhero tropes.

Juvenalian Satire

Juvenalian satire, in literature, any bitter and ironic criticism of contemporary persons and institutions that is filled with personal invective, angry moral indignation, and pessimism. The name alludes to the Latin satirist Juvenal, who, in the 1st century ad, brilliantly denounced Roman society, the rich and powerful, and the discomforts and dangers of city life. Samuel Johnson modeled his poem London on Juvenal’s third satire and The Vanity of Human Wishes on the 10th. Gulliver’s Travels (1726) established Jonathan Swift as the master of Juvenalian satire. In the 20th century, Karl Kraus’s indictments of the prevailing corruption in post-World War I Austria were in the Juvenalian tradition.

[emphasis mine]

Brittanica

If anger is your energy—for instance, if you wanted to subvert the status quo and attack the venality of the political class or religious leaders—then Juvenalian satire is your best bet. Freed from the shackles of being outright funny, the mission of Juvenalian satire is often to attack individuals, governments and organisations to expose hypocrisy and moral transgressions. For this reason, writers should expect to use stronger doses of irony and sarcasm in this concoction.

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