>Double Battles are the standard, which immediately makes battles much faster (on paper, since I don't remember being able to disable Battle Animations in those games) and gives much more room for viability in some species of Pokemon
>most major foes actually attempt to utilize a strategy, even if it's something basic whereas current mainline games just throw 2-3 Offensive Moves on a Pokemon and call it a day
>game isn't afraid to throw actual challenges at you, especially the final bosses
>rather than handing out Free Nukes or blatantly superior Pokemon 24/7, you have to get by with what the game presents you, leading to potential discovery of underrated Pokemon and making the best of what you have
Unfortunately, thanks to the "IT MUST BE ACCESSIBLE TO BRAINDEAD RETARDS" Mentality we'll never see anything quite like it again.