.

Interfaces/ICurrentLevel.cs

@@ -1,7 +1,9 @@
+using R3;
+
 namespace GodotHostTest.Interfaces;
 
 public interface ICurrentLevel
 {
-    public int LevelNumber { get; }
+    public ReadOnlyReactiveProperty<int> LevelNumber { get; }
     public void NextLevel();
 }

Interfaces/IScore.cs

@@ -1,3 +1,5 @@
+using R3;
+
 namespace GodotHostTest.Interfaces;
 
 /// <summary>
@@ -8,5 +10,5 @@ public interface IScore
     /// <summary>
     /// The current score.
     /// </summary>
-    public int Score { get; }
+    public Observable<int> Score { get; }
 }

Interfaces/ITarget.cs

@@ -8,12 +8,13 @@ namespace GodotHostTest.Interfaces;
 public interface ITarget
 {
     /// <summary>
-    /// The target hasn't been hit in the allotted time and has timed out.
+    /// The target hasn't been hit in the allotted time and has timed out; once this observable emits an event, both
+    /// it and <see cref="Hit"/> complete.
     /// </summary>
     Observable<Unit> TimedOut { get; }
-    
+
     /// <summary>
-    /// The target has been hit.
+    /// The target has been hit; once this observable emits an event, both it and <see cref="TimedOut"/> complete.
     /// </summary>
     Observable<Unit> Hit { get; }
 

Interfaces/ITargetEventBus.cs

@@ -0,0 +1,22 @@
+using R3;
+
+namespace GodotHostTest.Interfaces;
+
+public interface ITargetEventBus
+{
+    /// <summary>
+    ///     A target has timed out and disappeared.
+    /// </summary>
+    Observable<Unit> TimedOut { get; }
+
+    /// <summary>
+    ///     A target has been hit.
+    /// </summary>
+    Observable<Unit> Hit { get; }
+
+    /// <summary>
+    ///     A new target spawner has been added.
+    /// </summary>
+    /// <param name="targetSpawner"></param>
+    void NewTargetSpawner(ITargetSpawner targetSpawner);
+}

Interfaces/ITargetEventBus.cs.uid

@@ -0,0 +1 @@
+uid://bgexc7hcs5r4n