Hi I've just finished a 100% collectibles speedrun of Gylt and I was wondering if a 100% category could be added so I can post my run, please?

Only the game’s mod can add a new category. However, this game’s mod is inactive. For now, go ahead and submit your 100% run to the any% category, and if it isn’t reviewed then you can take further action.

https://www.speedrun.com/gylt/full_game

Well that's a shame. Thank I will do that, wish me luck.