A "Ponzi scheme" is a form of fraud in which a purported businessman lures investors and pays profits to earlier investors using funds obtained from newer investors. Investors may be led to believe that the profits are coming from product sales, or other means, and remain unaware that other investors are the source of apparent profits. A Ponzi scheme is able to maintain the illusion of a sustainable business as long as most of the investors do not demand full repayment and are willing to believe in the non-existent assets that they are purported to own, and there continues to be new investors willing to contribute new funds.
** "Ether" is a cryptocurrency whose blockchain is generated by the Ethereum platform. Ether can be transferred between accounts and used to compensate participant mining nodes for computations performed. Ethereum provides a decentralized Turing-completevirtual machine, the Ethereum Virtual Machine (EVM), which can execute scripts using an international network of public nodes. "Gas", an internal transaction pricing mechanism, is used to mitigate spam and allocate resources on the network.

That's mean, that Project "333 ETH" is not a "Ponzi Sheme", because there is no person, no a company (businessman), who
"pays profits to earlier investors using funds obtained from newer investors"...

It's smart-contract algorithm (program code funtcion) on which the project is based is uploaded to the blockchain Ethereum 03.09.18 with the OWNERSHIP WAIVER function ("REFUSAL of OWNERSHIP"). This means that nobody - including the organizers- can't access it to tamper with its independent functioning.

Also, Admins does not have access to the main purse of the contract, it does not have the opportunity to withdraw funds from the smart-contract. Admins does not engage in the rescheduling of the ether* among the participants - it's function of the independent smart-contract.

Project "333 ETH" isn't working with world currency of exchange (like USD or Euro), smart-contract "333 ETH" is distribution of Ether* between participants (ether can be transferred between accounts and used to compensate participant mining nodes for computations performed).

However, the most important component of the "Ponzi scheme" is FRAUD... As you can see - in this case it is excluded...