Speaking of types, I hate how useless Steel was offensively before Fairies. It's only good against rocks, but rock type pokemon and ice types, but rocks usually pack Earthquake which is super effective against Steel types and ice types usually have high special attack, which Steel types lack. The leaked Spaceworld beta actually had much different take on both Dark and Steel, for example Fighting was not super effective against Steel and two Steel types cancel each other out completely, instead of being not very effective(this was switched with Poison type, which was merely not very effective in the beta). Dark type was also interesting, since Normal type and other Dark types were super effective against it, making Normal actually useful.
BTW I recommend SuperGold97 if you want to experience the beta yourself, it was largely complete and all it took to complete it was some polish. The beta type chart and pokemon are at full display, and that makes the game not only interesting but also gives a whole lot of new thought towards teambuilding(Dark types are not as important but Normal types actually have a purpose now). Interesting tidbit is that you actually get to visit not just Johto and Kanto but also Hoenn and Sinnoh, with a couple locations taken from DPP almost directly due to them being restored Spaceworld content in those games.