diff --git a/demo/Demo.cpp b/demo/Demo.cpp
index 1284ec5..12f14d4 100644
--- a/demo/Demo.cpp
+++ b/demo/Demo.cpp
@@ -12,7 +12,8 @@
   changed, gradients, level select code input, logging, variable screen
   resolution, debug display, loading wheel animation, shadowed sprite, separate
   update and draw, sprite movement cage, multiple windows, multiple renderers,
-  node children list, node animations list
+  node children list, node animations list, copy constructor for node, private
+  and public class members
 
   :) SWEATY HANDS :) OILY SNACKS :) AND BAD HYGIENE :)
 
diff --git a/src/Color.hpp b/src/Color.hpp
index 7051a46..161ced6 100644
--- a/src/Color.hpp
+++ b/src/Color.hpp
@@ -14,7 +14,7 @@ struct Color
     std::uint8_t r, g, b, a;
 
     Color();
-    Color(std::uint8_t, std::uint8_t, std::uint8_t, std::uint8_t);
+    Color(std::uint8_t, std::uint8_t, std::uint8_t, std::uint8_t = 255);
     Color(const SDL_Color&);
     void set_rgb_float(const float&, const float&, const float&);
     void set_hsv(const float&, const float& = 1.0f, const float& = 1.0f);
diff --git a/src/Configuration.cpp b/src/Configuration.cpp
index 9bbfe36..bdc79fa 100644
--- a/src/Configuration.cpp
+++ b/src/Configuration.cpp
@@ -42,7 +42,9 @@ void Configuration::set_defaults()
         {"dimensions", {640, 480}},
         {"framerate", 60},
         {"title", "sfw"},
-        {"debug", false}
+        {"debug", false},
+        {"show-cursor", false},
+        {"render-test-spacing", 2}
     };
     sys_config["recording"] = {
         {"enabled", false},
diff --git a/src/Game.cpp b/src/Game.cpp
index 1d934ed..a5f5505 100644
--- a/src/Game.cpp
+++ b/src/Game.cpp
@@ -44,7 +44,7 @@ void FramerateIndicator::refresh()
     }
 }
 
-Game::Game() : Node()
+Game::Game()
 {
     frame_length_history.reserve(5000);
     set_framerate(get_configuration()["display"]["framerate"]);
@@ -75,16 +75,37 @@ Game::Game() : Node()
     SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
     SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
     print_gl_attributes();
-    std::vector<int> window_size = get_configuration()["display"]["dimensions"];
+    auto window_size = get_configuration()["display"]["dimensions"].get<glm::ivec2>();
     window = SDL_CreateWindow(
         get_configuration()["display"]["title"].get_ref<const std::string&>().c_str(), SDL_WINDOWPOS_CENTERED,
-        SDL_WINDOWPOS_CENTERED, window_size[0], window_size[1], SDL_WINDOW_OPENGL);
+        SDL_WINDOWPOS_CENTERED, window_size.x, window_size.y, SDL_WINDOW_OPENGL);
     if (window == NULL)
     {
         print_sdl_error("Could not create window");
         flag_to_end();
     }
-    SDL_ShowCursor(0);
+    if ((renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_TARGETTEXTURE)) == NULL)
+    {
+        print_sdl_error("Could not create renderer");
+        flag_to_end();
+    }
+    else
+    {
+        SDL_SetRenderTarget(renderer, NULL);
+        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+        SDL_RenderClear(renderer);
+        int step = get_configuration()["display"]["render-test-spacing"];
+        for (int x = 0, r = 1, g = 0, b = 2; x < window_size.x; x += step)
+        {
+            SDL_SetRenderDrawColor(renderer, (r++ % 3 == 0) * 255, (g++ % 3 == 0) * 255, (b++ % 3 == 0) * 255, 255);
+            const SDL_Rect rect = {x, 0, step, window_size.y};
+            SDL_RenderFillRect(renderer, &rect);
+        }
+        SDL_RenderPresent(renderer);
+        SDL_RenderFlush(renderer);
+        SDL_DestroyRenderer(renderer);
+    }
+    SDL_ShowCursor(get_configuration()["display"]["show-cursor"]);
     if (TTF_Init() < 0)
     {
         print_sdl_error("Could not initialize SDL ttf");
diff --git a/src/Game.hpp b/src/Game.hpp
index c35c81d..bd65e09 100644
--- a/src/Game.hpp
+++ b/src/Game.hpp
@@ -13,23 +13,19 @@
 
 #define GL_GLEXT_PROTOTYPES
 #define GLEW_STATIC
-
 #if defined(__EMSCRIPTEN__)
-
 #include <emscripten.h>
 #include <emscripten/html5.h>
 #include <GL/glew.h>
-
 #else
-
 #include "glew/glew.h"
-
 #endif
 
 #include "Node.hpp"
 #include "Input.hpp"
 #include "Recorder.hpp"
 #include "Sprite.hpp"
+#include "extension.hpp"
 
 struct FramerateIndicator : Sprite
 {
diff --git a/src/Node.cpp b/src/Node.cpp
index 3b681c0..6f5c92b 100644
--- a/src/Node.cpp
+++ b/src/Node.cpp
@@ -3,7 +3,7 @@
 
 Node::Node() : Node(NULL) {}
 
-Node::Node(Node *parent) : parent(parent)
+Node::Node(Node* parent) : parent(parent)
 {
     std::cout << "Constructing ";
     print_branch();
@@ -61,12 +61,12 @@ const Input& Node::get_input() const
 
 const Game* Node::get_root() const
 {
-    const Node* root = this;
-    while (root->parent != NULL)
+    const Node* r = this;
+    while (r->parent != NULL)
     {
-        root = parent;
+        r = r->parent;
     }
-    return dynamic_cast<const Game*>(root);
+    return dynamic_cast<const Game*>(r);
 }
 
 Box Node::get_window_box()
diff --git a/src/extension.hpp b/src/extension.hpp
index 35ee3e7..4195dc7 100644
--- a/src/extension.hpp
+++ b/src/extension.hpp
@@ -18,6 +18,7 @@
 #include "glm/trigonometric.hpp"
 #include "glm/vec2.hpp"
 #include "glm/gtx/vector_angle.hpp"
+#include "json/json.hpp"
 
 #include "Box.hpp"
 #include "Segment.hpp"
@@ -158,6 +159,22 @@ bool operator<(const SDL_Color& color_1, const SDL_Color& color_2);
 bool operator==(const SDL_Color& color_1, const SDL_Color& color_2);
 std::ostream& operator<<(std::ostream&, const SDL_Color&);
 
+namespace glm
+{
+    template <typename T>
+    void to_json(nlohmann::json& j, const vec<2, T, defaultp>& v)
+    {
+        j = nlohmann::json{{"x", v.x}, {"y", v.y}};
+    }
+
+    template <typename T>
+    void from_json(const nlohmann::json& j, vec<2, T, defaultp>& v)
+    {
+        j.at(0).get_to(v.x);
+        j.at(1).get_to(v.y);
+    }
+}
+
 #include "Node.hpp"
 
 #endif