I've written an in-browser program for making animated plasma patterns. It's not really a game as such but at least to me it's a fun way to waste a few minutes. Is it something I can post on itch.io or is breaking the rules? I'm still working on it so the controls are still a bit rough
 

Hi,

To try to answer the question of “Does it have to be a game?”… Itch has categories other than Games as well (including an Other category). I tend to browse books, comics, and physical games, myself.

I didn't get yelled at for the GG3MC so I think you're fine. https://godwaygames.itch.io/godway-games-3d-mesh-creator
I think if I was doing something wrong by expressing that I was going to release a non-game, they would've said something by now considering how long it's been up on here already.

It absolutly doesn't have to be a game! You probably would have to put it under the games category because it's the closest match, but make sure you change the games pronoun to whatever you think matches it best. Let me know when you release the pattern generator, it looks pretty cool.

I've thought about it a bit and I'd rather keep it under Games rather than Other. I think I can do that by having an optional story mode, which is effectively a tutorial for the controls taking you through what effectively starts as just boring balls bouncing off each other to adding connecting lines, arcing the lines, adding visual after fx  and a few other things, but it loosely makes it a game  where you complete the optional story mode to open up freeform mode.