Yeah it's more like a PVP. Well I was trying to search but I can not find any projects like this. Maybe this system will be flawed? Anyway if there is only one participant, when the round is over, he gets his money back. Everything happens automatically. It's written in the smart contract. Only if the contract has not enough balance to pay the gas plus the user's share would be a problem. But for that, we could add a function that everyone can topup the contract's account for fees.
Maybe a good concept but since this is a PVP scheme you need to establish your reputation and promote your project to gain more players, I don't think it will gain a lot of followers, gamblers are more convenient to play on regular casinos because they are guaranteed of payment since you mention that it will run in smart contract I don't think the majority are convenient to play a game connecting their wallet in a contract.
You will have a hard time convincing people here to play without solid plan that the game will not be rigged, trust is one of the problem of newbies coming up with a game like this.
I see what you mean. Most people are not technical enough to see that the smart contract is not rigged. Maybe if it got audited by some reputable company, they would trust?
But anyway another concern that I have, let's say in the 10 minute round, there was 5 participant, but a user deposited 4 times from different addresses, so he will have higher chance to win the deposit of that 1 user? Or maybe actually he takes more risk because if that 1 user is in the winner list, he could be screwed. But since the distribution is not equal, it's fine. I am thinking about this logic.