I do not think this is a scam in terms of any criminal code. Polybius founders did not assure that market price of Polybius tokens will rise or that their bank will be profitable. They did not promise to register a bank successfully; they promised to try to register it depending on decision of regulator.

"It works on Emercoin" means that Polybius founders want to use Emercoin NVS (blockchain name-value storage) as the decentralized database for storing their public keys, transactions etc.

They could decide to use a centralized database (like MySQL) and say that "it works on MySQL so Oracle is our partner".

As for Emercoin founder Oleg Khovayko, it is suspicious that Polybius use the same Khovayko's photo that is pulished on Emercoin website.