To paraphrase. Use your best judgement.
You are a coder. You should be capable of recognising if you use ai code or not.
And if you are one of those "vibe coders", yeah, that's ai coding at the fullest.
Prompting search to give you the textbook example of a function you want to use and adapting that result in your code, is not, imho, even if the result was generated by an ai. But if you ask the ai to write the functions with your parameters and copy the result, it is.
AI does not make a game slop. It's the human that releases a slop game. And there are plenty of human made slop games too. It's just that the slop game creators can make a lot of these with ai in a short time. Itch is self publishing which means that there is no publisher that would block low effort slop. In theory the quality guidelines would deny indexing for slop. But distinguishing an amateur game from professional slop ain't easy.