anchor.diff:                  if (monsters_killed < 10) {
                       //spawnMonster(new GridPoint(0,0), new Zombie(this, false));
                       spawnRandomMonster( (p) {
  -                        return dg.grid.getSquare(p).isEmpty()
  -                               && (p.x != 1 || p.y != 1);
  +                        return dg.grid.getSquare(p).isEmpty() // square has to be empty
  +                               && (p.x != 1 || p.y != 1)      // only spawn monsters in the borders
  +                               && (p.x != last_monster_death.x
  +                                   && p.y != last_monster_death.y);
                       });
                   } else {
                       dg.status.updateStatus(dg.ctx, "You Killed all monsters. Game over :)");
  
positive.code: }
  
  // TODO:
  // x show attack
  
  void main() {
  
negative.code:     bool hero_is_dead;
      bool game_over;
      int monsters_killed;
      GridPoint last_monster_death;
      Random rng;
  
      DungeonState(this.dg)
  