Swing the Sword

import random
import pygame

TILE = 48
MAP = [
    "##############",
    "#............#",
    "#.P......K...#",
    "#............#",
    "#....##......D",
    "#....##......#",
    "##.#######.###",
    "#............#",
    "#...S....H...#",
    "##############",
]

pygame.init()
screen = pygame.display.set_mode((672, 480))
pygame.display.set_caption("Rune Keep")
clock = pygame.time.Clock()
font = pygame.font.Font("assets/fonts/pixel.ttf", 32)


def load(name):
    return pygame.image.load("assets/images/" + name).convert_alpha()


floor_img = load("floor.png")
wall_img = load("wall.png")
knight_img = load("knight.png")
door_img = load("dungeon_door.png")
key_img = load("key.png")
slime_img = load("slime.png")
spider_img = load("spider.png")
heart_img = load("heart.png")
empty_img = load("heart_empty.png")
sword_img = load("sword.png")
potion_img = load("potion_red.png")


def draw(image, rect):
    screen.blit(image, image.get_rect(center=rect.center))


def cell_rect(col, row):
    rect = pygame.Rect(0, 0, 32, 32)
    rect.center = (col * TILE + 24, row * TILE + 24)
    return rect


class Enemy(pygame.sprite.Sprite):
    def __init__(self, image, rect, dx, dy):
        super().__init__()
        self.image = image
        self.rect = rect
        self.dx = dx
        self.dy = dy

    def update(self, blocks):
        self.rect.x += self.dx
        self.rect.y += self.dy
        if self.rect.collidelist(blocks) != -1:
            self.rect.x -= self.dx
            self.rect.y -= self.dy
            self.dx = -self.dx
            self.dy = -self.dy


class Room:
    def __init__(self, lines):
        self.walls = []
        self.enemies = pygame.sprite.Group()
        self.start = (72, 72)
        self.has_key = False
        self.door_open = False
        for row, line in enumerate(lines):
            for col, char in enumerate(line):
                if char == "#":
                    self.walls.append(pygame.Rect(col * TILE, row * TILE, TILE, TILE))
                elif char == "P":
                    self.start = cell_rect(col, row).center
                elif char == "K":
                    self.key = cell_rect(col, row)
                elif char == "D":
                    self.door = pygame.Rect(col * TILE, row * TILE, TILE, TILE)
                elif char == "S":
                    speed = random.choice([-2, 2])
                    self.enemies.add(Enemy(slime_img, cell_rect(col, row), speed, 0))

    def blocks(self):
        if self.door_open:
            return self.walls
        return self.walls + [self.door]


class Knight(pygame.sprite.Sprite):
    def __init__(self, center):
        super().__init__()
        self.image = knight_img
        self.rect = pygame.Rect(0, 0, 32, 32)
        self.rect.center = center
        self.hearts = 3
        self.hurt = 0

    def move(self, dx, dy, blocks):
        self.rect.x += dx
        for block in blocks:
            if self.rect.colliderect(block):
                if dx > 0:
                    self.rect.right = block.left
                elif dx < 0:
                    self.rect.left = block.right
        self.rect.y += dy
        for block in blocks:
            if self.rect.colliderect(block):
                if dy > 0:
                    self.rect.bottom = block.top
                elif dy < 0:
                    self.rect.top = block.bottom


room = Room(MAP)
knight = Knight(room.start)
state = "playing"

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    if state == "playing":
        keys = pygame.key.get_pressed()
        dx = 0
        dy = 0
        if keys[pygame.K_LEFT]:
            dx = -3
        if keys[pygame.K_RIGHT]:
            dx = 3
        if keys[pygame.K_UP]:
            dy = -3
        if keys[pygame.K_DOWN]:
            dy = 3
        knight.move(dx, dy, room.blocks())
        knight.rect.clamp_ip(screen.get_rect())

        if not room.has_key and knight.rect.colliderect(room.key):
            room.has_key = True
        if room.has_key and knight.rect.inflate(8, 8).colliderect(room.door):
            room.door_open = True

        room.enemies.update(room.walls + [room.door])

        if knight.hurt > 0:
            knight.hurt -= 1
        elif pygame.sprite.spritecollide(knight, room.enemies, False):
            knight.hearts -= 1
            knight.hurt = 60
            if knight.hearts == 0:
                state = "lost"

    for row in range(10):
        for col in range(14):
            screen.blit(floor_img, (col * TILE, row * TILE))
    for wall in room.walls:
        screen.blit(wall_img, wall)
    if not room.door_open:
        screen.blit(door_img, room.door)
    if not room.has_key:
        draw(key_img, room.key)
    for enemy in room.enemies:
        draw(enemy.image, enemy.rect)
    if knight.hurt % 10 < 5:
        draw(knight.image, knight.rect)
    for i in range(3):
        if i < knight.hearts:
            screen.blit(heart_img, (8 + i * 40, 6))
        else:
            screen.blit(empty_img, (8 + i * 40, 6))
    if room.has_key:
        screen.blit(key_img, (136, 6))
    if state == "lost":
        message = font.render("Game over", True, (240, 240, 240))
        screen.blit(message, message.get_rect(center=(336, 240)))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()