While we are at it I love the leaderboard as is (sans cheating of course), but I think leaderboards for each character on each level/ overall would be cool as well. Just think of being atop the tofu boy leaderboard with 2 beaten levels (totally a guess, I know he can't beat the first level but there has to be one or two he can beat somewhere...).
Sorry to toss a wrench into this idea, but if you strip out the glitch, boss and warps, you are left with 250 levels. Each of these levels has an individual leaderboard. 250 is fairly respectable, but making each level have a dozen leaderboards is just ludicrous. It's definitely more than plausible, but still a bit extreme and unnecessary. Plus this would totally alter the way the grand total time is calculated (and I really have no intention of time grinding every level with every character. I'd rather enjoy the new portal and editor).