You're very confidently assuming facts not even vaguely in evidence.
IIRC, he claimed he had a fully implemented engine. An engine is not necessarily (or even generally) a game;
you don't recall correctly.
he explicitly said "We have a working game that we will complete and deliver in a timely fashion."
So apparently lot being able to live up to your promises is the same as deliberate deception. Okay.
it's true, distinguishing mere breach of promise from fraud is a classic problem in law.
typically the elements of fraud are something like:
(1.) that the defendant made a representation,
(2.) as to a material fact,
(3.) which was false,
(4.) and known to be false by the defendant,
(5.) that the representation was made for the purpose of inducing the other party to rely upon it,
(6.) that the other party rightfully did so rely,
(7.) in ignorance of its falsity
(8.) to his injury
so the prima facie case for fraud here is something like, "Josh said there was already a working game (obviously material to the subject of if a game would ever be finished), and told all sorts of additional stories about things he had done this game, and there wasn't, and he hadn't. Josh knew there was no such game and that he had obviously never played this nonexistent game, yet he made all these false statements for the purpose of convincing people to back the KS. Maybe he intended to eventually make the game, but in September 2014, he knew he hadn't. Backers were within their rights to take these statements at face value, and certainly had no idea they were false. As a result they backed the KS and lost money."
There's nothing on its face unreasonable about this; it sets out the prima facie case for fraud, and all of the specifics that could be within the knowledge of the plaintiff at the outset of the suit.