Bug report: I opened the menu (X) and went to my pokemon during the mewtwo cutscene, and that caused everything to be quite buggy... my pokemon info was overlaid on top of mewtwo's dialogue, and at the fight setup, I could make them disappear when moving them around...
More reports:
1. Continuing a run showed different NPCs. Likely unintentional? Some interactions seemed somewhat broken. I spoke to the guy by the first bookshelf, but it seemed like I had to press Z a lot before anything advanced (unintentional?). I also talked to the guy who had Roxie as a coach; it seemed like an interaction with two NPCs, but the guy had a wall to his right, so I only saw dialogue from one of the pair.
2. Delcatty's Fake Out does not seem to trigger.
Some more bugs, in Battle Frontier:
3. Thunder shock's adjacency damage doesn't break Illusion.
4. Battle Frontier music sometimes doesn't loop correctly?
5. The opposing pokemon sometimes show the wrong level. Hovering over it shows a different level on the card, presumably the correct one.
6. Sometimes when initially choosing the pokemon move to use during a battle, both move options show up darkened.
7. I somehow caused the pokemon and move selection/auto-battle/pre-battle/start battle/shop/items/quit game menu to become out-of-sync, where the fading in-and-out rectangle became one unit to the right of the actual selected option. It's probably related to the item selection screen, since when I went back to the item selection screen and back out, the display fixed itself.