I think the criticism is unwarranted, at least some of it.
In the previous games, they asked plenty of questions. In this one, they didn't know it would be a game of choices because for the first time, the player wasn't someone directly implicated in the classroom soul-slipping incident. Up to now, they didn't have a reason to believe anyone could be a "god", so it makes sense for them not to be on their guard with people who aren't connected with class 2-B or the school.
There's also the fact that Kurose was pretty detailed in outlining the rules before beginning, and afterwards the matter of what happens if a word is guessed wrong is moot, because without his own kidneys and Yuzuru's face also missing, Tasuku has no choice but to play, come what may.
As for the crime of fraud… I actually thought about that and I think the question is similar to the philosophical question of "does a falling tree in the forest make a sound if there's nobody to listen to it?". I think direct experience is a component of some crimes, like murder or property damage (when the victim is the experiencer) and crossing on the red (when the criminal is the experiencer). But in others, the direct experience is linked to awareness, like the crime of fraud. A crime implies an untoward consequence and entrenchment on someone else's rights (to life, to property etc.), but in the case of fraud, consequences have to be acknowledged as untoward, or the victim won't experience the injustice. If you cheat someone out of their house, the consequence is pretty obvious, but if you tell a white lie to your mother about spending lunch money on flowers for your girlfriend, then the cheated party may never experience any consequence unless they become aware they were cheated. It seems to me that Tasuku's gamble wasn't a far-fetched one.