Ok, I think most of the potential challenges with this game has already been pointed out here. Lovecraft’s Cthulhu certainly is a somewhat crowded franchise. A new game has to bring something new to the table to be interesting. Modular adventure sites, like in other YZ games, have been mentioned. That could be interesting if it’s done well.
But what I’m mainly thinking of is a simple but cruisal question: who are the PCs supposed to be? That’s central to all YZ games, and I’m quite sure it will be in this game too. Could it perhaps be something else than a group of investigators? Perhaps people who aren’t on a mission, but involved in other ways? That would certainly be more unexpected. Maybe something could be found in Lovecraft’s own work. To really rethink the conventional group is probably hard, but interesting if it could be done.
As said in some of the interviews, there will be a premise similar to Alien in this game - short stories (cinematic) and campaign mode. A way to make the campaign part more interesting, could be to focus on a couple of well fleshed out NPCs and their agendas. Perhaps characters from Lovecraft novels and short stories? I’m thinking of characters like a mad professor, a cult leader or someone who have been affected by the Mythos in some other way. Knowing such a person could be a starting point for the PCs. It would be both true to Lovecraft’s fiction and something we haven’t really seen in any of the other games. Just adding another organisation, like The Society in Vaesen, wouldn’t be that surprising since it’s already been done in many other games. And in a game based on written fiction, it would make sense if some characters were a part of the basic framework. Instead of a traditional RPG base, you could develop a ship, a library, a museum, or even a family legacy (maybe in several generations) - and all this should be connected to a powerful NPC.
So what I’d prefer is something more than Call of Cthulhu with YZ rules. It’s rather a game that’s even closer to Lovecraft’s fiction.