They just see obvious AI (which I don't hide) and scream "SLOP!
If the platform bans AI, it would be normal for them to ban it. But calling it slop is unnecessary. If the platform allows AI, complain to the platform about the moderators.
For newgrounds, they do ban prompt generated movies.
AI Animation
Any work that appears to be largely generated by a prompt will be removed
our goal is that the majority of the work is human-made and not AI-made
Apparantly no one told them, that digital movies are almost never human made. Giving instructions to a rendering software is not technically human made, but human instructed. Which would be literally what a prompt does with more luxury. The time when something like 2d cartoons were human drawn and then just photographed to make a movie are gone. I know what they mean, but it is poorly worded.
Speaking of photography, does a photographer create an image? How does that compare to a painter that does create a painting by hand? In the olden days, painters even mixed the paint themselves. How about the artistic value of a photo image? There can be no doubt that it is now considered as art, but how do images taken with a phone fit in the story? Every person now has the ability to just press a button on their always accessible pocket device and create an image in a second that has better accuracy than a traditional oil on canvas painter might create in a week. And with no skill in painting whatsoever.
Yes, even a child can operate an ai prompt. And we cannot call any output of such an activity art, just as we cannot call every selfie a piece of art. But still, there is skill than can be applied in operating the ai. It is different skills than painting with oil on canvas or than holding a stylus on a tablet or than composing textures in a rendering software. But skill nontheless. And with skill comes the possibilty to apply that skill masterfully, which is the root of art.
What you did or try to do is exploring that application of ai. You did not just try to recreate a thing a traditional artist could have done.
Itch is centered about games and not art. The closest thing that might apply are jams that are about games with ai. Like this one https://itch.io/jam/ai-game-jam-2 . And of course those experimental games that use ai for other things than assets.