Recently I started figuring out how you get a large amount of credits in the first level. I think there should be level categories based on the number of credits you earn in an individual level, and that the person with the highest number of credits gets to be at the top of the leaderboard for those levels. Is there a way to add points on speedrun.com, whereas the person who got the most points gets to be on the top of the leaderboard?

You can put individual level leaderboards, and just put the amount of credits/points amassed in the milliseconds section, if that's what you mean