Optimize tower entity checking

game/systems/s_entity.c

@@ -372,7 +372,11 @@ void updateTower(ecs_iter_t *it) {
             }
         }
 
-        if (target == 0) continue;
+        if (target == 0) {
+            const f32 CHECK_INTERVAL = 0.2f; // 5 times a second
+            tower[i].fireElapsed = tower[i].fireCooldown - CHECK_INTERVAL;
+            continue;
+        }
 
         Vector2 dir = Vector2Subtract(targetPos, center);
         dir = Vector2Normalize(dir);