Loading time differences when it comes to RTA timing, as well as general emulator inaccuracies - and probably the biggest point for both this game and Black Knight is that you can remap the motion controls and put everything on buttons, which is not how the game was meant to be played. Not to mention the advantages you get from that. There can always be emulator categories added if there's demand, though. Don't let that stop you from running on emulator if you want, you just won't be able to submit those runs to this board.
tbh Im pretty new to this stuff even though i use emulator these days, but I dont think everyone would have wii or wii u to do them. ofc i still speedrun the game pretty much i think that as starter timer still have continue keep going even if we use different wii or wii u or emulator. I know its banned since there is no change to that I get it same time as long being pb and having a good in real game time is fine.
