And there are many changes in that episode as well. It´s longer than episode 12, that´s for sure, and probably longer than 11. Dunno about the others, didn´t join that early ^^
This episode added many nice field-effects, that beryl library, changed a few locations of some pokes, made nights brighter and added those nice street lights (I really think they look nice, even though there´s only like big white dots or smth ^-^). I also noticed some character-sprites look different.
If this episode is too short, try catching each and every single nre pokemon, get all pokedex-entries you can get and look for the new stuff that was added into the reborn city and take a look at the new/changed events. That might add a few hours If not, then just wait for the next episode or restart the game and try nuzlocke try something else, like different teams or I dunno ^-^