During its E3 Direct, Nintendo revealed that Dragon Quest XI S: Echoes of an Elusive Age will launch on Switch on September 27, 2019.
The definitive edition features an expanded storyline with new monsters to ride (like a giant pea), adds the ability to speed up battles, and lets you travel to past Dragon Quest worlds.
Dragon Quest XI S lets players toggle between 3D and 16-bit versions of the game on the fly. Check out screenshots demonstrating that feature here. The Definitive Edition also includes both English and Japanese voiceover and fully orchestrated field and battle music.