Updated asteriods, mines, and explosions.

AlientAttack.MonoGame/Things/SpriteUpdateContext.cs

@@ -12,6 +12,7 @@ public class SpriteUpdateContext(AlienAttackGame game)
     public required Action<Sprite> SpawnSprite { get; init; }
     public required Random Random { get; init; }
     public required GameTime GameTime { get; init; }
+    public float DeltaTime => (float)GameTime.ElapsedGameTime.TotalSeconds;
     public required ContentManager Content { get; init; }
     public AudioManager AudioManager => game.Audio;
     public required Player Player { get; init; }