I was just looking into the categories and noticed that Pure Hero and Pure Dark runs only take the final stage into account; GUN Fortress for the Pure Dark category and Final Haunt for Pure Hero. Apart from that, you can go for whatever path and whatever boss.

With that being said though, how about a proposal for what I like to call True categories? By this I mean, with the Dark run you have to complete all the Dark missions, all Hero missions for the Hero run, and then there's the Neutral one. All Neutral missions is probably the norm here as the goal is always at the Goal Ring, so to make things a little more interesting for the Neutral run, maybe make sure Dark and Hero points are equal, or even no Dark or Hero points at all?

Those categories (All Hero/Dark Missions) exist, and BlazinZzetti has done runs of them, but it isn't worth putting on the leaderboard when there's only one run so far,

Ah, OK. Hopefully there will be more, and I'll start doing some when I get the chance too. Good luck though.

If you haven't found them yet. Here are the links to my Only Hero and Only Dark runs.

Only Hero Missions w/ CCG: Only Dark Missions w/ CCG: Only Hero Missions (No CCG): Only Dark Missions (No CCG):

These are commentary videos for marathon submissions so you might learn a thing or two about the game watching them. Assuming my commentary is actually good.

Regarding your Neutral idea, it might be better to think of it as a Pacifist run where you beat the game by only fighting enemies that prevent progress. So boss and the enemies that triggers a door or something. That run likely wont ever make it onto the boards here, but it does sound like a fun challenge.

Only Hero Missions and Only Dark Missions will likely make their way into the misc. category section once there's a run that isnt just mine.

I was thinking this for a while now, perhaps I'll do pure hero/dark sometime myself.