It's a really fun game! The only thing I found annoying from a game design point of view was the randomness as it leaves you clueless whether you just had pure luck or if the prompt was on the right track.
To other gamers: I'm not sure if there's really a secondary AI attempting to block the output or if it's a combination of both. If it's just a secondary model blocking the output, I wouldn't expect it to block outputting a single letter from the secret?