Sonic/Mega Man: Worlds Collide: The Complete Epic is a graphic novel that reprints the entirety of the first Sonic the Hedgehog and Mega Man crossover story, Worlds Collide. It includes all 12 chapters of the story plus the preludes and epilogues from both series'.
Prelude: Mega Man
The last ten pages of "For the 'Bot Who Has Everything" (MM: #23)
The final two pages of "Forged in Fire" (SU: #50) and three additional pages created using portions from other existing material (see background information for details)
"When Worlds Collide: Part 1- Kindred Spirits" (MM: #24)
"When Worlds Collide: Part 2- Mistaken Identities" (SU: #51)
"When Worlds Collide: Part 3- Homefield Advantage" (StH: #248)
"When Worlds Collide: Part 4- Through the Looking Glass" (MM: #25)
Awakening: Mega Man
The first three pages of "The Return: Prelude to Ra Moon" (MM: #28)
The first three pages of "At All Costs: Part 2- A New Lease on Life" (StH: #252)
Sonic's prologue consists of the final two pages of SU#50, plus three pages made entirely of material from other issues.
The first is a full page shot of Eggman pondering, telling somebody to ready the interdimensional portal, and that "Albert better be ready" (said dialogue lifted from StH#247). Eggmans artwork comes from page twelve of StH#257.
The second shows Sonic and Tails watching in bewilderment as everything around them fades to white: Sonic utters his line from the end of #247, "Oh no, this is-". The (slightly altered) poses are lifted from page eight of StH#252.
The third page depicts Sonic and Mega Man both being blinded by a flash of light (representing the Genesis Wave). Both poses are lifted from MM#25: Sonic's from page three, and Mega Man's from page eleven.
The titles of both the prologue and epilogue stories are not actually used in the book: the titles are listed above for clarity.
Early listings for the book were initially very different from the final product: originally, two versions of the book were planned to be released, alternately titled "Worlds Collide: Deluxe Edition" and "Worlds Collide: Super Deluxe Edition", with it being implied the latter would have additional content.
Sonic's final line in the epilogue is changed from the original full comic version. His original line of "If we're back in the city and here to save the King...", which originally concluded on the following page with "...does that mean Naugus is involved?", is changed to a simple "Something strange is going on here...", due to the fact the story cuts off before the following page.