As noted there are services such as
- PlayFab (Microsoft based) - GameLift (Amazon based) - GameSparks - Photon - etc
All of these have some level of "developer" capacity that lets you get started for free. That said they are not designed to be a free server host like you are sugesting
You can create a networked game without using a 3rd party service such as the ones listed above by using one of the freely available and opensourced HLAPIs.
- [Mirror][1] - [Mirage][2] - [MLAPI][3]
All of the above can be used to create P2P network structurs or Client/Server strucutres. In P2P (Peer to Peer) there is no server/service between the players they simply connect directly to each other and that means there is no need for serever hosting or paying a 3rd party. It does mean you have to deal with routing and the likes but that isn't a problem with a LAN game and there are various guides for handling it in other situations.
All of the tools noted also have big communities so easy to learn [1]: https://api.unity.com/v1/oauth2/authorize?client_id=asset_store_v2&locale=en_US&redirect_uri=https%3A%2F%2Fassetstore.unity.com%2Fauth%2Fcallback%3Fredirect_to%3D%252Fpackages%252Ftools%252Fnetwork%252Fmirror-129321&response_type=code&state=d404bef2-a956-4ad3-980b-9e4fe3ae72b2 [2]: https://github.com/MirageNet/Mirage [3]: https://docs-multiplayer.unity3d.com/docs/getting-started/about-mlapi/index.html
- PlayFab (Microsoft based) - GameLift (Amazon based) - GameSparks - Photon - etc
All of these have some level of "developer" capacity that lets you get started for free. That said they are not designed to be a free server host like you are sugesting
You can create a networked game without using a 3rd party service such as the ones listed above by using one of the freely available and opensourced HLAPIs.
- [Mirror][1] - [Mirage][2] - [MLAPI][3]
All of the above can be used to create P2P network structurs or Client/Server strucutres. In P2P (Peer to Peer) there is no server/service between the players they simply connect directly to each other and that means there is no need for serever hosting or paying a 3rd party. It does mean you have to deal with routing and the likes but that isn't a problem with a LAN game and there are various guides for handling it in other situations.
All of the tools noted also have big communities so easy to learn [1]: https://api.unity.com/v1/oauth2/authorize?client_id=asset_store_v2&locale=en_US&redirect_uri=https%3A%2F%2Fassetstore.unity.com%2Fauth%2Fcallback%3Fredirect_to%3D%252Fpackages%252Ftools%252Fnetwork%252Fmirror-129321&response_type=code&state=d404bef2-a956-4ad3-980b-9e4fe3ae72b2 [2]: https://github.com/MirageNet/Mirage [3]: https://docs-multiplayer.unity3d.com/docs/getting-started/about-mlapi/index.html