If AI is generating a significant portion of your code, then it's good to indicate this out of respect for your users.
If your use of AI is marginal, for example, optimizing something you created or helping you with small goals, such as showing you syntax you don't remember or simplifying repetitive tasks, then it's generally accepted that the AI was an additional tool and not the creator of the code. In these cases, it's not usually mentioned.
Not all users want to play games created with AI, and it's out of respect for them that it's good to indicate this.
The problem is that many developers want to take advantage of the benefits of creating a game with AI, but they don't want to risk losing players. That's cheating, because you know you're hiding sensitive information that benefits you and "harms" your players.
Out of respect for your users, be honest. Many players don't care whether the code or the art was created by an AI. Go for those players, but respect the decision of those who don't want games created by AI. And if you really want to reach this second segment of players, then don't use AI.
EDIT:
Regarding cheating, let's see, unless it's a competition or you're hiding information, it's simply the way you work.
Going back to the example given above, if a basketball player had that machine in a professional tournament, then it would be cheating.
If, on the other hand, it's simply a friendly tournament and all the players have access to that machine, and the people watching them KNOW they're going to use that machine, then it wouldn't be cheating, because you're not hiding information or having an unfair advantage.
I'd say it's the same here. If you like using AI, let them know with the appropriate TAGs, and if you participate in a JAM, make sure it's one that allows the use of AI. As long as you respect those rules, I don't see you cheating.