diff --git a/source/animated_sprite.cpp b/source/animated_sprite.cpp
index a818d81..d671202 100644
--- a/source/animated_sprite.cpp
+++ b/source/animated_sprite.cpp
@@ -510,8 +510,11 @@ void AnimatedSprite::setCurrentAnimation(int index)
 // Actualiza las variables del objeto
 void AnimatedSprite::update()
 {
-	animate();
-	MovingSprite::update();
+	if (enabled_)
+	{
+		animate();
+		MovingSprite::update();
+	}
 }
 
 // Establece el rectangulo para un frame de una animación
diff --git a/source/game.cpp b/source/game.cpp
index 0a3c879..c3c4b43 100644
--- a/source/game.cpp
+++ b/source/game.cpp
@@ -1049,7 +1049,7 @@ void Game::updateBalloonSpeed()
 }
 
 // Explosiona un globo. Lo destruye y crea otros dos si es el caso
-void Game::popBalloon(std::shared_ptr<Balloon> &balloon)
+void Game::popBalloon(std::shared_ptr<Balloon> balloon)
 {
 	// Aumenta el poder de la fase
 	increaseStageCurrentPower(1);
@@ -1072,11 +1072,11 @@ void Game::popBalloon(std::shared_ptr<Balloon> &balloon)
 		}
 		else
 		{ // En cualquier otro caso, crea dos globos de un tipo inferior
-			const auto bLeft = createBalloon(0, balloon->getPosY(), balloon->getKind() - 1, BALLOON_VELX_NEGATIVE, enemySpeed, 0);
+			auto bLeft = createBalloon(0, balloon->getPosY(), balloon->getKind() - 1, BALLOON_VELX_NEGATIVE, enemySpeed, 0);
 			bLeft->allignTo(balloon->getPosX() + (balloon->getWidth() / 2));
 			bLeft->setVelY(bLeft->getClass() == BALLOON_CLASS ? -2.50f : BALLOON_VELX_NEGATIVE);
 
-			const auto bRight = createBalloon(0, balloon->getPosY(), balloon->getKind() - 1, BALLOON_VELX_POSITIVE, enemySpeed, 0);
+			auto bRight = createBalloon(0, balloon->getPosY(), balloon->getKind() - 1, BALLOON_VELX_POSITIVE, enemySpeed, 0);
 			bRight->allignTo(balloon->getPosX() + (balloon->getWidth() / 2));
 			bRight->setVelY(bRight->getClass() == BALLOON_CLASS ? -2.50f : BALLOON_VELX_NEGATIVE);
 
diff --git a/source/game.h b/source/game.h
index 4a6989b..5f9423c 100644
--- a/source/game.h
+++ b/source/game.h
@@ -277,7 +277,7 @@ private:
 	void updateBalloonSpeed();
 
 	// Explosiona un globo. Lo destruye y crea otros dos si es el caso
-	void popBalloon(std::shared_ptr<Balloon> &balloon);
+	void popBalloon(std::shared_ptr<Balloon> balloon);
 
 	// Explosiona un globo. Lo destruye
 	void destroyBalloon(std::shared_ptr<Balloon> &balloon);
diff --git a/source/moving_sprite.cpp b/source/moving_sprite.cpp
index 2eeb42e..44ce667 100644
--- a/source/moving_sprite.cpp
+++ b/source/moving_sprite.cpp
@@ -68,7 +68,10 @@ void MovingSprite::move()
 // Muestra el sprite por pantalla
 void MovingSprite::render()
 {
-	texture_->render((int)x_, (int)y_, &spriteClip_, zoomW_, zoomH_, angle_, center_, currentFlip_);
+	if (enabled_)
+	{
+		texture_->render((int)x_, (int)y_, &spriteClip_, zoomW_, zoomH_, angle_, center_, currentFlip_);
+	}
 }
 
 // Obtiene el valor de la variable
@@ -259,9 +262,12 @@ void MovingSprite::disableRotate()
 // Actualiza las variables internas del objeto
 void MovingSprite::update()
 {
-	move();
-	rotate();
-	++counter_ %= 60000;
+	if (enabled_)
+	{
+		move();
+		rotate();
+		++counter_ %= 60000;
+	}
 }
 
 // Cambia el sentido de la rotación
diff --git a/source/screen.cpp b/source/screen.cpp
index e70cd30..a44ca7c 100644
--- a/source/screen.cpp
+++ b/source/screen.cpp
@@ -232,7 +232,7 @@ void Screen::setVideoMode(ScreenVideoMode videoMode)
     // Reinicia los shaders
     if (options.video.shaders)
     {
-#ifdef SHADERS
+#ifndef NO_SHADERS
         std::ifstream f(asset->get("crtpi.glsl").c_str());
         std::string source((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
 
diff --git a/source/smart_sprite.cpp b/source/smart_sprite.cpp
index 168ae22..bbfa0e1 100644
--- a/source/smart_sprite.cpp
+++ b/source/smart_sprite.cpp
@@ -19,20 +19,18 @@ void SmartSprite::init()
 	destX_ = 0;
 	destY_ = 0;
 	finished_ = false;
+	enabled_ = false;
 }
 
 // Actualiza la posición y comprueba si ha llegado a su destino
 void SmartSprite::update()
 {
-	MovingSprite::update();
-	checkMove();
-	checkFinished();
-}
-
-// Pinta el objeto en pantalla
-void SmartSprite::render()
-{
-	MovingSprite::render();
+	if (enabled_)
+	{
+		MovingSprite::update();
+		checkMove();
+		checkFinished();
+	}
 }
 
 // Establece el valor de la variable
diff --git a/source/smart_sprite.h b/source/smart_sprite.h
index a64ff52..16d4ece 100644
--- a/source/smart_sprite.h
+++ b/source/smart_sprite.h
@@ -34,9 +34,6 @@ public:
 	// Actualiza la posición y comprueba si ha llegado a su destino
 	void update();
 
-	// Pinta el objeto en pantalla
-	void render();
-
 	// Establece el valor de la variable
 	void setFinishedCounter(int value);