>>23169588My opinion. Gen IV introduced so many things that really changed how the game could be played. A big, cozy region located at the northest part of PokeJapan that would make you feel you were having an enjoyable and relaxing trip thanks to the amazing piano and jazz music.
Physical/Special split and Wi-Fi are probably, until today, the two biggest enhancements Pokemon has received, being finally able to trade and battle with friends all over the world was a dream come true, while the split helped every single Pokemon become relevant since now they didn't depend in attack types to deal respective damage.
If you were into competitive, Gen IV brought the best metagame there has been until now, you could see versatile teams, experimentation, a nice balance between offense and stall.
Evolutions to old Pokemon brought them back from being forgotten, giving them boosts, nice designs and with the physical/special split, they would all have a chance to shine.
Underground was a very fun and addicting minigame. Go down, mine and get stones and fossils, you could spend hours in there just digging to your heart's desire.
And more stuff like a very good postgame of descent length, daily hordes, Pokeball Seals, Contests, Battleground for Gym Leader rematches, GTS, Poketch and a very interesting mythology where they just went overboard by introducing a literal God and Creator and expanding it with bits to leave to speculation.
As an anon a few posts ago said, it was way too fun to notice the slow battle speeds. Right now is a huge deal, but before it was nothing compared to all the stuff it brought to the series.
