feat: add Unity project (Assets, ProjectSettings)

game/Assets/Scripts/Survival/DeathZone.cs

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+using UnityEngine;
+
+/// <summary>
+/// Survival mode: a rising death zone that climbs from below.
+/// The server is authoritative on the Y position (broadcast via NetworkState.deathZoneY).
+/// This component moves the visual/collider locally, and detects local player contact.
+///
+/// Setup: Create a large Plane or Cube GameObject, attach this script,
+/// add a Box/Mesh Collider set to "Is Trigger".
+/// The object will be positioned at deathZoneY each frame.
+/// </summary>
+public class DeathZone : MonoBehaviour
+{
+    [Header("Visual")]
+    [Tooltip("Half-size of the death zone plane (X and Z)")]
+    public float halfExtent = 200f;
+
+    [Tooltip("Thickness of the zone collider")]
+    public float thickness = 2f;
+
+    [Header("Warning")]
+    [Tooltip("Distance above death zone where the red tint starts")]
+    public float warningDistance = 8f;
+
+    private bool _hitSent = false;
+    private float _targetY = -100f;
+
+    void Start()
+    {
+        // Scale the collider to cover the arena
+        transform.localScale = new Vector3(halfExtent * 2f, thickness, halfExtent * 2f);
+
+        // Subscribe to death zone Y changes from server
+        if (NetworkManager.Instance != null)
+        {
+            NetworkManager.Instance.OnDeathZoneYChanged += OnDeathZoneYChanged;
+            NetworkManager.Instance.OnPhaseChanged += OnPhaseChanged;
+        }
+    }
+
+    void OnDestroy()
+    {
+        if (NetworkManager.Instance != null)
+        {
+            NetworkManager.Instance.OnDeathZoneYChanged -= OnDeathZoneYChanged;
+            NetworkManager.Instance.OnPhaseChanged -= OnPhaseChanged;
+        }
+    }
+
+    void OnDeathZoneYChanged(float y)
+    {
+        _targetY = y;
+    }
+
+    void OnPhaseChanged(string phase)
+    {
+        if (phase == "playing" || phase == "lobby")
+        {
+            _hitSent = false; // reset for new round
+        }
+    }
+
+    void Update()
+    {
+        // Smooth follow of the server Y value
+        Vector3 pos = transform.position;
+        pos.y = Mathf.Lerp(pos.y, _targetY, Time.deltaTime * 3f);
+        transform.position = pos;
+
+        // Update warning tint based on local player proximity
+        var nm = NetworkManager.Instance;
+        if (nm != null && nm.IsConnected && GameHUD.Instance != null)
+        {
+            var localState = nm.GetLocalPlayerState();
+            if (localState != null)
+            {
+                float dist = localState.y - pos.y;
+                float intensity = Mathf.Clamp01(1f - dist / warningDistance);
+                GameHUD.Instance.SetDeathZoneWarning(intensity);
+            }
+        }
+    }
+
+    void OnTriggerEnter(Collider other)
+    {
+        if (_hitSent) return;
+        if (other.GetComponent<PlayerController>() == null) return;
+
+        _hitSent = true;
+        Debug.Log("[DeathZone] Local player hit the death zone!");
+        NetworkManager.Instance?.SendDeathZoneHit();
+    }
+}

game/Assets/Scripts/Survival/DeathZone.cs.meta

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+fileFormatVersion: 2
+guid: 99fdfaa3e87a64d4e958f81014e6cdab