Positives:
Like the graphics so far. Captures the 'HD Kanto' feeling quite well.
Following Pokemon? Hell yes.
Multiplayer in theory is quite a nice concept.
Customizable Pikachu and Eevee is cool I suppose.
Its easier to encounter the Pokemon you want thanks to them being clearly visible, which is one bonus of the Pokemon Go-styled mechanics. It also adds quite a bit to the immersion.
It seems like the main player characters now have a bit more emotion to them which is something I feel the Alola games should've done.
Negatives:
The catching mechanics are dumbed down thanks to this essentially being full-game Pokemon Go. There's no real risk involved outside of the Pokemon possibly just running away or you running out of Pokeballs. Wild encounters are fun because the Pokemon is trying to fight you back while you catch it, so you also run the risk of whiting out or having your Pokemon KOed.
Seemingly FireRed and LeafGreen style of remake, as in 'CAN'T EVOLVE YOUR GOLBAT UNTIL YOU BEAT THE GAME HERP DE DURR'. Still, with Tangela and Lickitung, how are they gonna handle the 'level up with a certain move' style of evolutions?
Pokeball accessory is tacky as hell and its novelty will likely run out quickly.
Having a 2nd Kanto remake in general is kinda a dumb idea, even if its nice to have an HD Pokemon Region.
Motion controls, even in switch mode.
For the record, I WAS personally annoyed by things like the Nugget Bridge reference in the Alola games (The Kantonian Gym from USUM not so much because they at least changed the mechanics a bit (with a fee plus there's no specific type) and its explained as more of a tribute rather than literally having Pokemon you can't catch like Pidgey and Weedle being used by Trainers for some unexplained reason). This game is its own contained thing rather than shoehorned references so I wouldn't say its EXACTLY like Malie Garden Nugget Bridge or Mega Kanto starters. Plus with it being its own contained game, and the announcement of Gen 8 games in 2019, both notable sides of the Pokemon fandom get their own game. (With this being for the casual Pokemon Go players (but wouldn't it be just a little bit nice to have SOME Johto and Hoenn Pokemon if that's the case?))