There are so many accusations of AI art use these days for no other reason than that, since some developers use it, people have begun to suspect absolutely everyone.
We are always open and honest about our work and we have never used AI for anything, anywhere. Our illustrator for this project is our art lead and game designer, the guy who sweats over and meticulously works out the narrative and setting of the game. He’s been drawing for over six years, and the whole saga of his growth as an artist is clearly recorded for all to see. What’s more, he continues to actively refine his skillset. Human beings can make minor mistakes with anatomy, shadows, etc., due to oversight or gaps in their knowledge. That’s a normal thing. It’s deeply upsetting for us to hear constant accusations of AI use being leveled at us simply because our wonderful artist happens to have a style that bears a cursory resemblance to certain AI art.
Honestly, kudos on not using AI, but even if you did it'd be fine. A game is about a lot more than just the art itself and the writing, character development, personalities, etc all matter as well. Anyone who'd snub a game just because it has AI generated art in it (which by the way takes time, effort, etc. on it's own to make it good.) clearly needs to take a step back. That's like watching only movies that have no CGI or digital special effects in them at all.
You are well within your rights to defend your artist and writers. I have to point out that being dedicated and talented does not exclude one from using AI. In some cases, it is because of the talent and hard work that people resort to help. Most notable example is the artist for a Dungeons and Dragons book. He drew and colored the art himself and used AI for a final filter and it left some noticable artifacts. Most people wouldn't touch steroids. Olympic athletes with fame, money, and drive for competition have more reason.
When I saw the artstyle I also had suspicions it might be AI generated; the fact that there is a credit section for voice work but no mention of an artist as far as I saw when skimming over it doesn't help that look.
Maybe just add credits for art and writing in addition to the voice work? That way people would know where to look.