NameError: name 'Mike' is not defined

def get_next_monster(self):
    try:
        return self.monsters.pop(0)
    except IndexError:
        return None

def monster_turn(self):
    # Check to see if the monster attacks
    # If so, tell the player
    if self.monster.attack():
        print('{} is attacking!'.format(self.monster))
        # Check to see if the player wants to dodge
        if input("Dodge? Y/N ").lower() == 'y':
            # If so, see if the dodge is successful. If it is, move on.
            if self.player.dodge():
                print('You dodged the attack!')
            # If it isn't lower hit points by one
            else:
                print('You got hit anyways!')
                self.player.hit_points -= 1
        else:
            print('{} hit you for 1 point!'.format(self.monster))
            self.player.hit_points -= 1
    # If the monster isn't attacking, tell that to the player        
    else:
        print("{} isn't attacking this turn.".format(self.monster))

def player_turn(self):
    # Let the player attack, rest, or quit
    player_choice = input('[A]ttack, [R]est, or [Q]uit? ').lower()
    # If they attack:
    if player_choice == 'a':
        print("You're attacking {}!".format(self.monster))
        # See if the attack is successful
        if self.player.attack():
            # If so, see if the monster dodges
            if self.monster.dodge():
                # If dodged, print that
                print('{} dodged your attack!'.format(self.monster))
            else:
                # If not dodged, subtract the right number of hit points from the monster
                if self.player.leveled_up():
                    self.monster.hit_points -= 2
                else:
                    self.monster.hit_points -= 1
                print("You hit {} with your {}!".format(self.monster, self.player.weapon))
        else:
            # If not a good attack, tell the player
            print('You missed!')

    # If they rest:
    elif player_choice == 'r':
        # Call the player.rest method
        self.player.rest()

    # If they quit, exit the game
    elif player_choice == 'q':
        sys.exit()

    # If they pick anything else, rerun this method
    else:
        self.player_turn()

def cleanup(self):
    # If the monster has no more hit points:
    if self.monster.hit_points <= 0:
        # Up the player's experience
        self.player.experience += self.monster.experience
        # Print the message
        print("You killed {}!".format(self.monster))
        # Get a new monster
        self.monster = self.get_next_monster()   

def __init__(self):
    self.setup()

    while self.player.hit_points and (self.monster or self.monsters):
        print('\n'+'='*20)
        print(self.player)
        self.monster_turn()
        print('-'*20)
        self.player_turn()
        self.cleanup()
        print('\n'+'='*20)

    if self.player.hit_points:
        print('You win!')
    elif self.monsters or self.monster:
        print('You lose!')
    sys.exit()

def attack(self):
    roll = random.randint(1, self.attack_limit)
    if self.weapon == 'sword':
        roll += 1
    elif self.weapon == 'axe':
        roll += 2
    return roll > 4

def get_weapon(self):
    weapon_choice = input("Weapon ([S]word, [A]xe, [B]ow): ").lower()

    if weapon_choice in 'sab':
        if weapon_choice == 's':
            return 'sword'
        elif weapon_choice == 'a':
            return 'axe'
        else:
            return 'bow'
    else:
        return self.get_weapon()

def __init__(self, **kwargs):
    self.name = input("Name: ")
    self.weapon = self.get_weapon()
    self.hit_points = self.base_hit_points

    for key, value in kwargs.items():
        setattr(self, key, value)

def __str__(self):
    return '{}, HP: {}, XP: {}'.format(self.name, self.hit_points, self.experience)

def rest(self):
    if self.hit_points < self.base_hit_points:
        self.hit_points += 1

def leveled_up(self):
    return self.experience >= 5