This generation, sadly, was my second least favorite generation. This is just a "retelling" of Generation I that has almost literally nothing to do with Generation I. This generation a huge step, TOO huge. They decided to never include the Pikachu family (WHO WOULD WANT TO ABANDON THE FREAKING MASCOT OF THE ENTIRE FRANCHISE), Abra, Magikarp, and a bunch of other ones I needn't explain.
Also, it's basically a 3D Kanto. It starts back at Route 1, has at least 150 Pokémon (which aren't related to other Pokémon from other generations. Really?), and even has a villainous team who plots on taking over the region! I'm also a little disappointed they didn't include anything like a Battle Frontier (Battle Subway just dumbs it down) and the fact that the PokéDex doesn't make sense at all. If only 156 Pokémon are native to the old Unova Dex, why the heck are Gens I-IV Pokémon just hanging around in the grass? Why do they also appear while fishing? Was Professor Juniper too lazy to check on the the other routes? It's also kinda sad that they didn't give the player characters much character development, either.
However, this generation brought a few things that were good. One example of this...
...is Palpitoad. What? Can't a guy have a favorite Pokémon?
Also, it introduced a LOT of competitive versatility, with cool new items and abilities.
I guess that's all I can say for now.