diff --git a/README.md b/README.md
index c536d55..0a3231d 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,26 @@
 Em breve, vídeo no YouTube explicando o código!
 
-Assets tirados de: https://github.com/sourabhv/FlapPyBird
\ No newline at end of file
+Assets tirados de: https://github.com/sourabhv/FlapPyBird
+
+
+## Instruções
+
+1. Criando ambiente virtual e inicializando;
+2. Instalando dependências;
+3. Executando o jogo.
+
+### Criando ambiente virtual e inicializando
+```
+virtualenv -p python3 env
+source env/bin/activate
+```
+
+### Instalando dependências
+```
+pip instal -r requirements.txt
+```
+
+### Executando o jogo
+```
+python ./flappy.py
+```
\ No newline at end of file
diff --git a/background-day.png b/assets/background-day.png
similarity index 100%
rename from background-day.png
rename to assets/background-day.png
diff --git a/base.png b/assets/base.png
similarity index 100%
rename from base.png
rename to assets/base.png
diff --git a/bluebird-downflap.png b/assets/bluebird-downflap.png
similarity index 100%
rename from bluebird-downflap.png
rename to assets/bluebird-downflap.png
diff --git a/bluebird-midflap.png b/assets/bluebird-midflap.png
similarity index 100%
rename from bluebird-midflap.png
rename to assets/bluebird-midflap.png
diff --git a/bluebird-upflap.png b/assets/bluebird-upflap.png
similarity index 100%
rename from bluebird-upflap.png
rename to assets/bluebird-upflap.png
diff --git a/pipe-red.png b/assets/pipe-red.png
similarity index 100%
rename from pipe-red.png
rename to assets/pipe-red.png
diff --git a/flappy.py b/flappy.py
index 30773f2..5e7ec98 100644
--- a/flappy.py
+++ b/flappy.py
@@ -15,22 +15,28 @@
 
 PIPE_GAP = 200
 
+IMG_BASE = 'assets/base.png'
+IMG_BACKGROUND = 'assets/background-day.png'
+IMG_BIRD_MIDFLAP = 'assets/bluebird-midflap.png'
+IMG_BIRD_UPFLAP = 'assets/bluebird-upflap.png'
+IMG_BIRD_DOWNFLAP = 'assets/bluebird-downflap.png'
+IMG_PIPE = 'assets/pipe-red.png'
+
+
 class Bird(pygame.sprite.Sprite):
 
     def __init__(self):
         pygame.sprite.Sprite.__init__(self)
 
-        self.images = [pygame.image.load('bluebird-upflap.png').convert_alpha(),
-                       pygame.image.load('bluebird-midflap.png').convert_alpha(),
-                       pygame.image.load('bluebird-downflap.png').convert_alpha()]
-
-        self.speed = SPEED
-
+        self.images = [pygame.image.load(IMG_BIRD_UPFLAP).convert_alpha(),
+                       pygame.image.load(IMG_BIRD_MIDFLAP).convert_alpha(),
+                       pygame.image.load(IMG_BIRD_DOWNFLAP).convert_alpha()]
         self.current_image = 0
 
-        self.image = pygame.image.load('bluebird-upflap.png').convert_alpha()
+        self.image = pygame.image.load(IMG_BIRD_UPFLAP).convert_alpha()
         self.mask = pygame.mask.from_surface(self.image)
 
+        self.speed = SPEED
         self.rect = self.image.get_rect()
         self.rect[0] = SCREEN_WIDTH / 2
         self.rect[1] = SCREEN_HEIGHT / 2
@@ -49,10 +55,10 @@ def bump(self):
 
 class Pipe(pygame.sprite.Sprite):
 
-    def __init__(self, inverted, xpos, ysize):
+    def __init__(self, xpos, ysize, inverted=False):
         pygame.sprite.Sprite.__init__(self)
 
-        self.image = pygame.image.load('pipe-red.png').convert_alpha()
+        self.image = pygame.image.load(IMG_PIPE).convert_alpha()
         self.image = pygame.transform.scale(self.image, (PIPE_WIDTH,PIPE_HEIGHT))
 
         self.rect = self.image.get_rect()
@@ -74,7 +80,7 @@ class Ground(pygame.sprite.Sprite):
     def __init__(self, xpos):
         pygame.sprite.Sprite.__init__(self)
 
-        self.image = pygame.image.load('base.png').convert_alpha()
+        self.image = pygame.image.load(IMG_BASE).convert_alpha()
         self.image = pygame.transform.scale(self.image, (GROUND_WIDTH, GROUND_HEIGHT))
 
         self.mask = pygame.mask.from_surface(self.image)
@@ -86,20 +92,22 @@ def __init__(self, xpos):
     def update(self):
         self.rect[0] -= GAME_SPEED
 
+
 def is_off_screen(sprite):
     return sprite.rect[0] < -(sprite.rect[2])
 
+
 def get_random_pipes(xpos):
     size = random.randint(100, 300)
-    pipe = Pipe(False, xpos, size)
-    pipe_inverted = Pipe(True, xpos, SCREEN_HEIGHT - size - PIPE_GAP)
+    pipe = Pipe(xpos, size)
+    pipe_inverted = Pipe(xpos, SCREEN_HEIGHT - size - PIPE_GAP, True)
     return (pipe, pipe_inverted)
 
 
 pygame.init()
 screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
 
-BACKGROUND = pygame.image.load('background-day.png')
+BACKGROUND = pygame.image.load(IMG_BACKGROUND)
 BACKGROUND = pygame.transform.scale(BACKGROUND, (SCREEN_WIDTH, SCREEN_HEIGHT))
 
 bird_group = pygame.sprite.Group()
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..ac7421d
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+pygame==2.0.1
\ No newline at end of file