The new world design really struggles with the fixed angle trainer battles. Perhaps one of the reasons PLA didn't have many trainer battles itself. The animations are definitely all designed like they are from a game where trainer battles always happen in a flat open field so weird things happen when you challenge a trainer on a slope. You'd think they'd get around this by only placing trainers in generally flat areas, but nope.
And its weird that the trainers all have their usual end of battle animations, but the game doesn't zoom in to let you see any of them. It does zoom in for the Gym Leaders, at least.
Framerate has noticeable issues, but it hasn't been a total deal breaker for me. I haven't experienced any of the really egregious stuff. I played long enough to get the first badge and then made sure to close the game out fully when I finished so hopefully I can avoid the really nasty stuff by only playing 3-4 hours at a time.
I'm going for my usual new generation experience of making my team of entirely new Pokemon, but it seems a number of the Pokemon I want in my final squad are in higher level areas so I might have to bend the rules to fill spots for a while.