Here is my room code:

import BaseRoom from "./BaseRoom";
import {Client} from "colyseus";

export class State {
    ticks: number;
    constructor() {
        this.ticks = 0;
    }
}

export default class ChatRoom extends BaseRoom<State> {
    onDispose(): void | Promise<any> {
        return undefined;
    }

    onInit(options: any): void {
        console.log('ChatRoom created');
        this.setState(new State());
        setInterval(() => {
            this.setState({ticks: this.state.ticks + 1});
            console.log('Updated state', this.state);
        }, 1000);
    }

    onJoin(client: Client, options?: any, auth?: any): void | Promise<any> {
        return undefined;
    }

    onLeave(client: Client): void | Promise<any> {
        return undefined;
    }

    onMessage(client: Client, data: any): void {
        console.log('ChatRoom received message', data);
    }
}

And on the Unity Side:

    Client client = new Colyseus.Client("ws://localhost:6900");
    client.OnError += Client_OnError;
    yield return StartCoroutine(client.Connect());
    Room room = client.Join("chat", new Dictionary<string, object>() {
        {"accessToken",accessToken},
        {"username", username}
    });
    room.OnReadyToConnect += (sender, e) => {
        Debug.Log("Ready to join room");
        StartCoroutine(room.Connect());
    };

    room.OnError += Room_OnError;

    room.OnStateChange += OnStateChange;
    room.Listen("message", this.OnMessage);
    room.Listen("ticks", this.OnTick);
    room.OnJoin += Room_OnJoin;
    room.OnMessage += Room_OnMessage;

    int i = 0;

    while (true)
    {
        client.Recv();

        i++;

        if (i % 50 == 0)
        {
            room.Send("some_command");
        }

        yield return 0;
    }

The the setState() method actually will overwrite the state - it doesn't work like React does. You'd usually mutate the state instead:

this.state.ticks++;

Hope this helps!

Maybe in the future! I'm currently working on TCP support to create a Game Maker client (they don't support WebSocket neither UDP)

It would need to be some sort of Reliable UDP, though. I'm still not sure how to go about it, since the order of messages are important.

Cheers!

    private void OnPlayerAdd(string key, Player newPlayer){
    newPlayer.TriggerAll();
    newPlayer.PlayerState.TriggerAll();

    if (!playersToAdd.ContainsKey(newPlayer.id))
    {
        playersToAdd.Add(newPlayer.id, newPlayer);

        if (newPlayer.Seatnumber != -1 && newPlayer.id == SessionId)
        {
           BoardManager.Instance.Enable_Disable(false);
           BoardManager.Instance.Set_up_profile(false, newPlayer.Seatnumber, playersToAdd[newPlayer.id]);
        }
    }

    if (newPlayer.id == SessionId && newPlayer.Seatnumber != -1)
    {
        thisSeat = newPlayer.Seatnumber;
        BoardManager.Instance.Rearrange_Seat();
    }

    if (GameplayRoom.State.players.Count >= 2)
    {
        BoardManager.Instance.WaitingTextDisable(false);
    }
    newPlayer.PlayerState.OnChange += changes =>
    {
        Debug.Log("-=-=-=-=-=-=-=-=-=-=-=-=-Player Log=-=--=-=-=-=-=-> " + key + " " + newPlayer.id);
        foreach (var t in changes)
        {
            Debug.Log(t.Field + " " + t.Value);
        }
    };
}

this is the code I have set on the client side
and This function is subscribe in "GameplayRoom.State.players.OnAdd += OnPlayerAdd;"