Sonic the Hedgehog/Mega Man: Worlds Unite Volume 3: Allied Forces was the intended third of three trade paperback releases of the Worlds Unite crossover. It contained reprints of stories from Sonic Universe #78, Sonic Boom #10, Sonic the Hedgehog #275, Mega Man #52. It was cancelled on 19 April 2017.
- The sequel to the record-shattering SONIC THE HEDGEHOG and MEGA MAN crossover is here! You saw what happened when WORLDS COLLIDE! Now brace yourself for when WORLDS UNITE! Sonic the Hedgehog and Mega Man have already teamed up with all their friends. They've even teamed up with the future's heroes from MEGA MAN X and the wild and wacky new characters from SONIC BOOM! Now everything. GETS. BIGGER! Heroes from across the SEGA and Capcom universes unite to battle the monstrous Sigma and stop his relentless assault across multiple universes! Featuring the worlds of STREET FIGHTER, GOLDEN AXE, MONSTER HUNTER, NIGHTS INTO DREAMS and many more! It's the dream team mash-up of iconic gaming heroes and villains you always hoped for in this frantic, bombastic finale! This volume collects WORLDS UNITE parts 9-12, including SONIC UNIVERSE #78, SONIC BOOM #10, SONIC THE HEDGEHOG #275, MEGA MAN #52 and selections from the SONIC THE HEDGEHOG: WORLDS UNITE BATTLES one-shot and includes bonus materials such as creator spotlights, production art, and 22 pages of cover images.
- The cover used for this volume is the same as the regular cover for Mega Man #52.