I would like to revive a thread because I think it is necessary for this game. I would like for adding individual worlds and levels for this game to be taken into consideration.

Levels already exist in the game itself, and quite good. Better than I did with DKCR. Worlds however, could be made a case for.

wouldn't it be nice to have them collected here, instead of having to boot up your copy of the game every time? and it would be easy to submit previous runs, considering the replay feature

I would really love if IW's (individual worlds) could be added. They would make really nice extra categories and would do well for practice

I did an Individual World speedrun of Lost Mangroves, and I must say it was fun! I really think IW's would make a good category and would lend shorter speedrun options for runners who don't want to do super long speedruns

Keeping the leaderboards for IL's in sync with the game, even with replays, is such a time-consuming task for a game that isn't as active as most marios, that's honestly not worth it.