If region maps as a whole count for something, then I'd definitely give that a mention. I think Audino also was an interesting feature, aiding those who have problems with grinding (as I do on days of poor health) to gain EXP without necessarily letting anyone breeze through the game.
Something else that I appreciate looking back is the fact that it felt like it could appeal to a larger demographic, considering that the plot could be considered a bit darker in comparison to, say, Gen 1. It did, however, keep the mood decent with the rivals and the soundtrack, which was incredibly fitting. I did make a thread about that, but I feel like promoting it would be a bit unnecessary. The repel mechanism and the recyclable TMs were really convenient, and I think that proved a lot less of a headache for gamers of any age.