Added some fun stuff that allows you to play with the time scale in Quake, either speeding it up or slowing it down from Unity.

Assets/Scripts/Bootstrap.cs

@@ -5,6 +5,8 @@ using UnityEngine;
 
 public class Bootstrap : MonoBehaviour
 {
+    private float speed = 1.0f;
+    
     private void Start()
     {
         Debug.Log($"Running in {IntPtr.Size * 8}-bit mode");
@@ -16,5 +18,13 @@ public class Bootstrap : MonoBehaviour
         {
             gameObject.AddComponent<Uniquake>();
         }
+
+        GUILayout.Label("Time scale:");
+        speed = GUILayout.HorizontalSlider(speed, 0.1f, 5.0f, GUILayout.Width(250));
+        GUILayout.Label($"{speed:0.00}");
+        if (!Mathf.Approximately(speed, Time.timeScale))
+        {
+            Time.timeScale = speed;
+        }
     }
 }

Assets/Scripts/Uniquake.cs

@@ -13,8 +13,12 @@ public class Uniquake: MonoBehaviour
     private QuakeParms quakeParms;
     private UnityCallbacks callbacks = new UnityCallbacks();
 
+    private static double startTime;    // TODO: this should be an instance field, but it requires a reference back to this object in the callbacks
+
     void Start()
     {
+        startTime = Time.timeAsDouble;
+        
         string[] arguments = 
         {
             "",
@@ -113,7 +117,7 @@ public class Uniquake: MonoBehaviour
     [AOT.MonoPInvokeCallback(typeof(RealtimeSinceStartupCallback))]
     private static double Callback_RealtimeSinceStartup()
     {
-        return Time.realtimeSinceStartupAsDouble;
+        return Time.timeAsDouble - startTime;
     }
 
     private class UnityCallbacks

engine/projects/uniquake/uniquake.c

@@ -63,9 +63,8 @@ UNIQUAKE_API void Uniquake_Init(const unity_callbacks_t *callbacks, quakeparms_t
 	unity_callbacks = callbacks;
 
 	COM_InitArgv(parms->argc, parms->argv);
-	// TODO winquake writes com_argc/argv back to parms.argc/argv, is this necessary?
-
-	isDedicated = true;
+	parms->argc = com_argc;
+	parms->argv = com_argv;
 
 	Host_Init(parms);
 }