Pokemon The Origin follows Red, and his journey with his Charmander. This is the Pokemon that we should have gotten because 1) Red is a winner. 2) Ash is a loser. 3)Red actually develops and learn something.
In four episodes, we relive the adventure that many of us experience as a kid - Pokemon Red Version (the better one) and Pokemon Blue Version.
The series starts off with Red as an inexperience trainer and as he journey to learn what it means to be a Pokemon Trainer. Also, Red and Green rivalry fuels both of them to catch em all and be the best trainer there ever was.
Spoiler - It's Red.
While the Origin does gloss over quite a few gym battles, the show does well at preserving the story in Red/Blue. Also, an element from X/Y is added to the show, so I'll let you fine folks watch that yourselves.
The animation itself differs from regular Pokemon show with Ash. It has a more mature and cleaner look to the animation versus the colorful and cutesy look in the regular Pokemon show.
Overall, this is the Pokemon that we should have gotten and I probably would still be watching it today if Pokemon told the story of Red/Green, Gold/Silver, Ruby/Sapphire, and so forth.