Mario: Fireball works

mario/visitors/goomba_visitor.hpp

@@ -17,6 +17,9 @@ public:
     bool isDead() const {
         return death;
     }
+    bool instantDeath() const {
+        return instant_death;
+    }
     void setFromId(uint64_t id) override {
         from = id;
     }
@@ -54,6 +57,7 @@ private:
     double groundY = 0;
     uint64_t _type{};
     bool death = false;
+    bool instant_death = false;
     uint64_t from = -1;
     bool left = false;
     bool right = false;