Okay, I played it, and somehow came out of it wanting to play the game LESS.
The "rival" is your now-standard way too chummy "instant best friends" piece of shit.
The evil team thing is done right for the first time since Rocket, based on just what I've seen from the demo. They're goofy as shit. It's not like Galactic, this time EVERYTHING ABOUT THEM is ridiculous. Their designs, their animations, their dialogue, everything. They were, against all odds, the best part of the demo.
The demo lets you do one of the "trials" that replaces gym battles. It's absolute garbage. You walk up to holes, take pictures of Pokémon, then battle a wild Pokémon your Greninja can OHKO.
so much better than gyms though right guys
You start with a Greninja with the "Battle Bond" ability, which turns it into Ash-Greninja after it takes out one Pokémon in the given battle.
Later, you get a Pikachu that is only there to show off Z moves in the worst way possible. "You just got thing? Very nice use it against this Golbat GOOD JOB Now let me take that Pikachu away before you hurt yourself and try to use the Z move in an interesting fashion :^)"
Remember in X/Y, when you'd hop onto a Rhyhorn or Mamoswine for a bit and stomp around? This time, they try and make that an actual thing throughout the game. You can just call on a Tauros anytime after you complete the trial and ride around.
The UI looks VERY nice. Shame about the "effective"/"not very effective"/"super effective" tags under moves that remove all thinking from single-player.
tl;dr
this game will sell millions but i'm not going to be one of those millions
waiting for 3ds emulation basically