Make game with Unity and Solidity

Hi. we want to make a game with Unity and integrate with blockchain.

1: in your Youtube channel i just saw 1 video about Unity, did you have a full SDK or API for unity as well as React or other languages?
2: You have a server. What happens when the server shuts down ? so in this case our Dapp is not Dapp! and doesn’t work. Right?
3: if you support Unity, what Version is good for working with metamask or other wallets in a game? For example Mobile version or OpenGL version?

there is a specific forum thread for questions about Unity SDK: Ethereum Unity3D Boilerplate Questions