Here's 13 (Used to be more but they finally moved them to the category extensions page) https://www.speedrun.com/smw
Does this count? It'd be 26 "categories" if it does
Do sub-categories count? This category has 38 sub-categories: https://www.speedrun.com/pringles#IRL
Come on guys, you've seen enough of my posts to know the answer is Streets Of Rage 4 https://www.speedrun.com/streets_of_rage_4/
For the full Arcade run, there are five difficulties plus a Boss Rush mode giving you six categories. Then multiply that by every character (17) and add on two different co-op modes and you have 19 x 6 = 114 basic categories.
But wait, there are actually two different versions of the game, so technically it is 228 categories as people can still run v4.
Beyond that, there is also the IL leaderboards. No two player mode for IL runs though (yet.....), so it is only ("only") 17 x 6 x 12 stages = 1,224 individual level categories.
So if you include full game and ILs together, there are no less than 1,452 ways to run Streets Of Rage 4.
Well, is it a question of total categories, or total categories combinations? Because in terms of categories alone, Streets of Rage don't stand out very much :)
If we're truly playing the combination game, surely this wins the cake though: https://www.speedrun.com/mcce
The whole leaderboard is a complete eye-sore for me, but it does fit the bill for this LUL
This doesn't beat MCCE but it's worth a mention because I think there are just gonna be more and more added https://www.speedrun.com/color_switch#ChallengesClassic
i was gonna say ootce ( https://www.speedrun.com/ootextras ) but yeah its definitely color switch