diff --git a/README.md b/README.md
index e33220a..29297b3 100644
--- a/README.md
+++ b/README.md
@@ -7,3 +7,4 @@ A dungeon crawler game made with LoveDOS for the DOSember Game Jam https://itch.
 - [Click.wav by frosty ham](https://opengameart.org/content/click-0)
 - [B&W Ornamental Cursor by qubodup](https://opengameart.org/content/bw-ornamental-cursor-19x19)
 - [Dogs of Cyberspace by congusbongus](https://modarchive.org/index.php?request=view_by_moduleid&query=207032)
+- [Microchip texture by ZeptoBARS](https://opengameart.org/content/microchip-texture)
diff --git a/imgs/cpu.png b/imgs/cpu.png
new file mode 100644
index 0000000..19adaf4
Binary files /dev/null and b/imgs/cpu.png differ
diff --git a/main.lua b/main.lua
index 5bf8aaf..ee63d47 100644
--- a/main.lua
+++ b/main.lua
@@ -1,46 +1,120 @@
----@diagnostic disable: undefined-global
-Mousex = 0
-Mousey = 0
-Cursor = nil
-Bgm = nil
-Click = nil
-Bckg = nil
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
 
+local love = require 'love'
+local game_states = require 'src.states'
+
+
+------------------------------------------------------------------------------
+-- Variables
+------------------------------------------------------------------------------
+
+Current_state = 1
+Fade_in = 0.0
+Fade_out = 1.0
+Change_state = false
+
+
+------------------------------------------------------------------------------
+-- Game methods
+------------------------------------------------------------------------------
+
+local function lerp(a, b, t)
+    -- Linear interpolation between two values a and b, by a t between 0.0 and 1.0
+    return (a * t) + (b * (1.0 - t))
+end
+
+
+------------------------------------------------------------------------------
+-- Game methods
+------------------------------------------------------------------------------
 
 function love.load()
-  Cursor = love.graphics.newImage('imgs/pointer.png')
-  Bckg = love.graphics.newImage('imgs/bckg.png')
+    game_states[Current_state]:load()
+end
 
 
-  Bgm = love.audio.newSource('bgm/dogs.wav')
-  Bgm:setLooping(true)
-  Bgm:play()
+function love.update(dt)
+    local new_state = game_states[Current_state]:update(dt)
 
-  Click = love.audio.newSource('snd/click.wav')
+    -- If the game state changed then trigger a fade out.
+    if new_state ~= Current_state and Fade_out >= 1.0 then
+        Fade_out = 0.0
+        Change_state = true
+    end
+
+    -- If there is a fade in going then update it.
+    if Fade_in < 1.0 then
+        Fade_in = Fade_in + (dt / 2)
+    end
+
+    -- If there is a fade out going then update it.
+    if Fade_out < 1.0 then
+        Fade_out = Fade_out + (dt / 2)
+    end
+
+    -- Update the game state.
+    if game_states[new_state] == nil then
+        -- If the new state doesn't exist then wait for the fade out to end and quit.
+        if Fade_out >= 1.0 then
+            game_states[Current_state]:unload(dt)
+            love.event.quit()
+        end
+    else
+        -- If the new state exists then unload it's data and set the new state.
+        if Change_state and Fade_out >= 1.0 then
+            game_states[Current_state]:unload(dt)
+            Current_state = new_state
+            game_states[Current_state]:load()
+            Change_state = false
+        end
+    end
 end
 
 
 function love.draw()
-  love.graphics.draw(Bckg, 0, 0)
-  love.graphics.draw(Cursor, Mousex , Mousey)
+    -- Reset the drawing color and clear the screen.
+    love.graphics.clear()
+
+    -- Render the current game state.
+    game_states[Current_state]:draw()
+
+    -- If there is a fade in going then render it.
+    if Fade_in < 1.0 then
+        love.graphics.setColor(0, 0, 0)
+        love.graphics.circle('fill', -320, love.graphics.getHeight() / 2, lerp(0, 400 * 2, Fade_in))
+        love.graphics.setColor()
+    end
+
+    -- If there is a fade out going then render it.
+    if Fade_out < 1.0 then
+        love.graphics.setColor(0, 0, 0)
+        love.graphics.circle('fill', -320, love.graphics.getHeight() / 2, lerp(400 * 2, 0, Fade_out))
+        love.graphics.setColor()
+    end
 end
 
 
 function love.keypressed(key)
-  if key == "escape" then
-    love.event.quit()
-  end
+    -- Send events to the active game state if there is no fade active.
+    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+        game_states[Current_state]:keypressed(key)
+    end
 end
 
 
 function love.mousemoved(x, y)
-  Mousex = x
-  Mousey = y
+    -- Send events to the active game state if there is no fade active.
+    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+        game_states[Current_state]:mousemoved(x, y)
+    end
 end
 
 
-function love.mousepressed(x, y, button)
-  if button == 1 then
-    Click:play()
-  end
+function love.mousepressed(x, y, btn)
+    -- Send events to the active game state if there is no fade active.
+    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+        game_states[Current_state]:mousemoved(x, y, btn)
+    end
 end
diff --git a/src/classes.lua b/src/classes.lua
new file mode 100644
index 0000000..0923b10
--- /dev/null
+++ b/src/classes.lua
@@ -0,0 +1,46 @@
+------------------------------------------------------------------------------
+-- Methods
+------------------------------------------------------------------------------
+
+-- Single inheritance version of the sample code from
+-- http://lua-users.org/wiki/ObjectOrientationTutorial
+local function make_class(BaseClass)
+    -- "cls" is the new class
+    local cls = {}
+
+    -- copy base class contents into the new class
+    if BaseClass ~= nil then
+        for k, v in pairs(BaseClass) do
+            cls[k] = v
+        end
+    end
+
+    -- set the class's __index, and start filling an "is_a" table that contains this class and all of its bases
+    -- so you can do an "instance of" check using my_instance.is_a[MyClass]
+    cls.__index, cls.is_a = cls, {[cls] = true}
+
+    if BaseClass ~= nil then
+        cls.is_a[BaseClass] = true
+    end
+
+    -- the class's __call metamethod
+    setmetatable(cls, {__call = function (c, ...)
+        local instance = setmetatable({}, c)
+
+        -- run the init method if it's there
+        local init = instance._init
+
+        if init then init(instance, ...) end
+        return instance
+    end})
+
+    -- return the new class table, that's ready to fill with methods
+    return cls
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return make_class
diff --git a/src/gstate.lua b/src/gstate.lua
new file mode 100644
index 0000000..6523738
--- /dev/null
+++ b/src/gstate.lua
@@ -0,0 +1,58 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.classes'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local GameState = make_class()
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function GameState:_init(name, index)
+    self.name = name
+    self.index = index
+    self.valid = false
+end
+
+
+function GameState:load()
+end
+
+
+function GameState:update(_)
+    return self.index
+end
+
+
+function GameState:draw()
+end
+
+
+function GameState:unload()
+end
+
+function GameState:keypressed(_)
+end
+
+
+function GameState:mousemoved(_, _)
+end
+
+
+function GameState:mousepressed(_, _, _)
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return GameState
diff --git a/src/intro.lua b/src/intro.lua
new file mode 100644
index 0000000..c039805
--- /dev/null
+++ b/src/intro.lua
@@ -0,0 +1,66 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love = require 'love'
+local make_class = require 'src.classes'
+local GameState = require 'src.gstate'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Intro = make_class(GameState)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Intro:_init(name, index)
+    -- Call super-class constructor.
+    GameState._init(self, name, index)
+
+    -- Attribute definitions
+    self.skip = false
+end
+
+
+function Intro:load()
+    self.background = love.graphics.newImage('imgs/cpu.png')
+    self.valid = true
+end
+
+
+function Intro:update(_)
+    if not self.skip then return self.index else return 0 end
+end
+
+
+function Intro:draw()
+    if self.valid then
+        love.graphics.draw(self.background, 0, 0)
+        love.graphics.print(string.format('OS: %s', love.system.getOS()), 5, 5)
+        love.graphics.print(string.format('Love version: %s', love.getVersion()), 5, 15)
+        love.graphics.print(string.format('Memory usage: %s KiB', love.system.getMemUsage()), 5, 25)
+    end
+end
+
+
+function Intro:unload()
+    self.background = nil
+    self.valid = false
+end
+
+
+function Intro:keypressed(_)
+    self.skip = true
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Intro
diff --git a/src/states.lua b/src/states.lua
new file mode 100644
index 0000000..700e4f2
--- /dev/null
+++ b/src/states.lua
@@ -0,0 +1,22 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local Intro = require 'src.intro'
+
+
+------------------------------------------------------------------------------
+-- Variables
+------------------------------------------------------------------------------
+
+-- Table of all valid game states.
+local states = {
+    Intro('intro', 1),
+}
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return states