When I run the game, it works for a bit but then when the first asteroid

gets to the bottom I get this:

Traceback (most recent call last):
  File "/root/making_with_code/mwc1/unit3/lab_retro/nav_game.py", line 14, in <module>
    game.play()
  File "/root/making_with_code/mwc1/unit3/lab_retro/retro/game.py", line 80, in play
    agent.play_turn(self)
  File "/root/making_with_code/mwc1/unit3/lab_retro/asteroid.py", line 16, in play_turn
    game.remove_agent_by_name(self.name)
AttributeError: 'Asteroid' object has no attribute 'name'

retro/agent.py

@@ -0,0 +1,99 @@
+class Agent:
+    """Represents a character in the game. To create an Agent, define a new
+    class with some of the attributes and methods below. You may change any of
+    the Agent's attributes at any time, and the result will immediately be 
+    visible in the game.
+
+    After you create your Agents, add them to the ``Game``, either when it is created
+    or using ``Game.add_agent`` later on. Then the Game will take care of calling 
+    the Agent's methods at the appropriate times. 
+
+    Attributes:
+        position: (Required) The character's ``(int, int)`` position on the game
+            board. 
+        character: (Required unless display is ``False``.) A one-character string 
+            which will be displayed at the Agent's position on the game board. 
+        name: (Optional) If an agent has a name, it must be unique within the game. 
+            Agent names can be used to look up agents with 
+            :py:meth:`retro.game.Game.get_agent_by_name`. 
+        color (str): (Optional) The agent's color. 
+            `Available colors <https://blessed.readthedocs.io/en/latest/colors.html>`_.
+        display: (Optional) When ``False``, the Agent will not be displayed on the 
+            board. This is useful when you want to create an agent which will be displayed
+            later, or when you want to create an agent which acts on the Game indirectly, 
+            for example by spawning other Agents. Defaults to True.
+        z: (Optional) When multiple Agents have the same position on the board, the 
+            Agent with the highest ``z`` value will be displayed. 
+            The Game is played on a two-dimensional (x, y) board, but you can think of 
+            ``z`` as a third "up" dimension. Defaults to 0.
+    """
+    character = "*"
+    position = (0, 0)
+    name = "agent"
+    color = "white_on_black"
+    display = True
+    z = 0
+
+    def play_turn(self, game):
+        """If an Agent has this method, it will be called once 
+        each turn. 
+
+        Arguments: 
+            game (Game): The game which is currently being played will be 
+                passed to the Agent, in case it needs to check anything about
+                the game or make any changes. 
+        """
+        pass
+
+    def handle_keystroke(self, keystroke, game):
+        """If an Agent has a this method, it will be called every
+        time a key is pressed in the game.
+
+        Arguments: 
+            keystroke (blessed.keyboard.Keystroke): The key which was pressed. You can 
+                compare a Keystroke with a string (e.g. ``if keystroke == 'q'``) to check 
+                whether it is a regular letter, number, or symbol on the keyboard. You can 
+                check special keys using the keystroke's name 
+                (e.g. ``if keystroke.name == "KEY_RIGHT"``). Run your game in debug mode to 
+                see the names of keystrokes. 
+            game (Game): The game which is currently being played will be 
+                passed to the Agent, in case it needs to check anything about
+                the game or make any changes. 
+            
+        """
+        pass
+
+class ArrowKeyAgent:
+    """A simple agent which can be moved around with the arrow keys.
+    """
+    name = "ArrowKeyAgent"
+    character = "*"
+    position = (0,0)
+    display = True
+    z = 0
+
+    def play_turn(self, game):
+        pass
+
+    def handle_keystroke(self, keystroke, game):
+        """Moves the agent's position if the keystroke is one of the arrow keys.
+        One by one, checks the keystroke's name against each arrow key. 
+        Then uses :py:meth:`try_to_move` to check whether the move is on the 
+        game's board before moving.
+        """
+        x, y = self.position
+        if keystroke.name == "KEY_RIGHT":
+            self.try_to_move((x + 1, y), game)
+        elif keystroke.name == "KEY_UP":
+            self.try_to_move((x, y - 1), game)
+        elif keystroke.name == "KEY_LEFT":
+            self.try_to_move((x - 1, y), game)
+        elif keystroke.name == "KEY_DOWN":
+            self.try_to_move((x, y + 1), game)
+
+    def try_to_move(self, position, game):
+        """Moves to the position if it is on the game board. 
+        """
+        if game.on_board(position):
+            self.position = position
+            game.log(f"Position: {self.position}")