In fact it should. Otherwise it lies by ommition. They put no effort into art, and they should state that. This is plagiarism, and it lacks originality. It is like selling idea that one heard online.
If we had to pay for the game, I would agree. Seeing as it is a free download, I don't see a problem with downloading and finding out. If the game was paid and he did not admit to the AI imagery, that is another story.
