From the moment The Hypocrites announced their plan to present all 32 of the surviving ancient Greek tragedies in one great marathon dubbed “All Our Tragic,” their undertaking was met with a sense of both overwhelming awe and terrified laughter. Were adapter-director Sean Graney and his company of 23 actors and musicians, his impressive design team and his small staff just plain nuts? Could they really carry it off?

Having now made my way through Sunday’s 12-hour epic opening (11 a.m. to 11 p.m. at the company’s handsome new home in a spacious storefront of The Den Theatre complex, I can report the answer to both questions is “Yes.” A Herculean labor for those on stage (the indefatigable ensemble, playing multiple major roles requiring total transformations, surely has set endurance records), as well as for the audience, “All Our Tragic” turns out to be a mind-boggling flight of the imagination, with many sequences of immense passion, intense physicality and wit.

Not surprisingly, it also contains many scenes that go on far too long, can seem repetitive, or overdo the “action comics” approach. Would a half-day marathon have been just as rewarding? Probably. (A one-page cheat-sheet with play titles and summary sentence also might be helpful.) Yet there is something about making it through the long slog (four “sections” comprised of several interlinking plays, with as many intermissions, as well as a half-hour lunch break and hourlong dinner break during which a buffet of Middle Eastern food is offered), that reinforces one of the plays’ over-riding themes: Human resilience.

Not by accident does this marathon begin with Prometheus (Geoff Button), who was punished by the gods for giving fire to man. Chained to a mountain, his liver was plucked out daily by birds of prey, but grew back each night, and he somehow prevailed.

In the many ensuing hours, we also witness countless examples of man’s astonishing inhumanity to man. On the intimate “family” scale there is the compulsion to love, and then to destroy the object of that love. Husbands and wives are a prime example. But the most horrifying situations involve parents who turn on their children, as with the baby-killing Medea (Dana Omar), or children who seek revenge, as Orestes (Button) and Elektra (Gavel) do with their mother, Klytaimnestra (Tien Doman).

On the grander scale there is the drive toward war, conflagrations often begun (as with the Trojan War) for ludicrous reasons, with carnage escalating until both sides reach mutual exhaustion and insanity. Consider Agamemnon (Walter Briggs), who sacrifices his adored and adoring daughter, Iphigenia (Lindsey Gavel), hoping the winds will shift and let his restless navy sail. More sheer madness comes in the memorable scene in which Ajax (Maximillian Lapine), a warrior with post-traumatic stress, slaughters a flock of sheep he mistakes for the enemy.

Other themes are crystallized as questions: Are the best leaders friendly, feared or faithful? Is forgiveness, especially for the most heinous crimes, possible?

It is well worth noting that neither the three playwrights whose work inspired this production (Aeschylus, Sophocles and Euripides), nor their translators, are mentioned in the program. To be sure, Graney has fully grabbed hold of their stories for his magnum opus, but from first to last he has put his unique, intensely unified stamp on it all with colloquial language and pop references that might make purists wince, and broad black comedy that DOES at times supplant “the tragic.” Yet his signature style eliminates all distancing formality and might lead a broader audience back to “the originals.” Along with those mentioned, Graney’s fearless, irrepressible actors include: Christine Stulik, Ezekiel Sulkes, Ryan Bourque, Luce Metrius, Erin Barlow, Emily Casey, Danny Goodman and John Taflan, plus six “Neo-Titans” executing Bourque’s killer fight choreography.

Often stealing the show is the female chorus, the “Odd Jobs,” who introduce major sequences with music. Erin Myers, Lauren Vogel and Kate Carson-Groner are bravura singers who move brilliantly from hymns and folk songs to opera while also playing accordion, guitar, banjo, flute and toy piano.

Alison Siple’s scores upon scores of costumes (love those goat-feet “boots”) are stellar, as are Tom Burch’s set and Jared Moore’s lighting.

Does anyone really know what it was like to attend the ancient Greek festivals of Dionysus held in those great stone amphitheaters that still exist? No. But Graney and The Hypocrites have given us their 21st century version of the experience. And it’s a doozy.