Lots of changes, forgot to add the heal scroll sound. Sounds for when enemies come in and go out of range. Menu filtering added.

src/constants.nvgt

@@ -119,6 +119,7 @@ const int INVASION_DURATION_HOURS = 1;
 const int BANDIT_DETECTION_RADIUS = 5;
 const int BANDIT_WANDER_DIRECTION_CHANGE_MIN = 3000;
 const int BANDIT_WANDER_DIRECTION_CHANGE_MAX = 8000;
+const int INVADER_SOUND_VARIANTS_MAX = 5;
 
 // Audio ranges and volume falloff
 // Formula: final_volume = start_volume - (volume_step × distance)