I'm actually not 100% sure how long it is, but I heard there were 10 chapters + 2 prologues. I've only finished up to Chapter 2 at the moment, but so far it looks like half of the chapters will be investigation-only, while the other half are trial-only. So yup, it's probably the same length as an average AA game! ^_^
Aw, but don't you want to see good ol' Edgeworth animated?? xD I'm currently re-watching one episode per day, kind of like an advent calendar haha. I've timed it in a way so I would be finished with the series on the day before the new season comes out. :D
Haha, you're not alone on that feeling! Although I very much enjoyed Sun/Moon, I've kinda gotten bored of the Pokémon main series games as a whole. xP Still love Mystery Dungeon to death, though!! <3
Ooooh, by the way! I think you'll like this, hehe:
https://www.youtube.com/watch?v=D4i4ETL-64I