enemy.py

import pygame
import random
from settings import *

class Enemy(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((30, 30))
        self.image.fill(RED)
        self.rect = self.image.get_rect()
        # Spawn at a random x location
        self.rect.x = random.randrange(SCREEN_WIDTH - self.rect.width)
        self.rect.y = random.randrange(-100, -40)
        self.speed_y = random.randrange(1, 5)

    def update(self):
        self.rect.y += self.speed_y
        # If it goes off the bottom, respawn it at the top
        if self.rect.top > SCREEN_HEIGHT + 10:
            self.rect.x = random.randrange(SCREEN_WIDTH - self.rect.width)
            self.rect.y = random.randrange(-100, -40)
            self.speed_y = random.randrange(1, 5)