-Following as the same "guidelines" in the other leaderboards of the "Sonic series", Sonic Riders: Zero Gravity will not include a "level leaderboard" or "IL leaderboard", as such, most people in the Sonic community uses "The Sonic Center" to track Individual Leves (or races in case of the the racing games), so if you would like to check/compete on that, I do recommend checking "The Sonic Center".
-As for the World Grand Prix leaderboard, as much I like the idea, I don't think would be "enough reason" to add it unless there is "enough" people to run the "category", plus, GP are more skip intensive as the "normal" story runs, I don't want to put a condition (or rather give a reason to work it to be added it), but, unless I see a GP run done that has a lower time to the current "best know time" (WR), I don't see GP leaderboards being a thing.
(Sorry if I sound kinda "harsh", but I just to make the clear about the reason and opinions of "why this and why not this".)
