diff --git a/game/main.lua b/game/main.lua
index 96def3f..53bfae1 100644
--- a/game/main.lua
+++ b/game/main.lua
@@ -1,9 +1,15 @@
 local world = {
-  require("src.world.race")(),
-  require("src.world.train")()
+  ["main_menu"] = require("src.world.main_menu")(),
+  ["race"] = require("src.world.race")(),
+  ["train"] = require("src.world.train")(),
 };
 
-local world_i = 1
+local world_i = "main_menu"
+
+function load_world(world_to_load)
+  world_i = world_to_load
+  world[world_i]:reload()
+end
 
 function love.load()
   world[world_i]:load()
@@ -18,13 +24,6 @@ function love.draw()
 end
 
 function love.keyreleased(key, scancode)
-  if (key == "right") then
-    world_i = world_i + 1
-    if (world_i > 2) then
-      world_i = 1
-    end
-    world[world_i]:reload()
-  end
   world[world_i]:keyreleased(key, scancode)
 end
 
diff --git a/game/src/world/common/component/button.lua b/game/src/world/common/component/button.lua
new file mode 100644
index 0000000..e299f6d
--- /dev/null
+++ b/game/src/world/common/component/button.lua
@@ -0,0 +1,30 @@
+local components = {}
+
+components.dict = {
+  collider = "button.collider",
+  func = "button.func",
+  label = "button.label"
+}
+
+function components.collider (c, x, y, w, h)
+  c.data = {
+    x = x or 0,
+    y = y or 0,
+    w = w or 0,
+    h = h or 0
+  }
+end
+
+function default()
+  print("click")
+end
+
+function components.func (c, func)
+  c.data = func or default
+end
+
+function components.label (c, label)
+  c.data = label or ""
+end
+
+return components
diff --git a/game/src/world/common/system/trigger_button.lua b/game/src/world/common/system/trigger_button.lua
new file mode 100644
index 0000000..a90ccd0
--- /dev/null
+++ b/game/src/world/common/system/trigger_button.lua
@@ -0,0 +1,81 @@
+local system_constructor = require("wrapper.Concord.system")
+local c_button = require("src.world.common.component.button")
+
+local system = {}
+
+system.__index = system
+
+system.pool = {
+  pool = {
+    c_button.dict.collider,
+    c_button.dict.func,
+    c_button.dict.label
+  }
+}
+
+system.components = {
+  [c_button.dict.collider] = c_button.collider,
+  [c_button.dict.func] = c_button.func,
+  [c_button.dict.label] = c_button.label
+}
+
+function system.new()
+  local new_system = system_constructor.new("trigger_button", system.pool)
+  if (new_system) then
+    for k, v in pairs(system) do
+		  new_system[k] = v
+	  end
+    return new_system
+  else
+    return nil
+  end
+end
+
+-- x1 y1        -- (x1 + w1) y1
+--          x2 y2
+-- x1 (y1 + h1) -- (x1 + w1) (y1 + h1)
+local function is_inside(x1,y1,w1,h1, x2,y2)
+  return x1 < x2 and
+         x2 < x1+w1 and
+         y1 < y2 and
+         y2 < y1+h1
+end
+
+function system:mousereleased(x, y, button, istouch, presses)
+  for _, e in ipairs(self.pool) do
+    local x1 = e[c_button.dict.collider].data.x
+    local y1 = e[c_button.dict.collider].data.y
+    local w1 = e[c_button.dict.collider].data.w
+    local h1 = e[c_button.dict.collider].data.h
+    local func = e[c_button.dict.func].data
+    if (is_inside(x1, y1, w1, h1, x, y) and button == 1) then
+      func()
+    end
+  end
+end
+
+local function draw(text, x, y, w, h)
+  love.graphics.push()
+  love.graphics.line(
+    x, y,
+    x + w, y,
+    x + w, y + h,
+    x, y + h,
+    x, y
+  )
+  love.graphics.print(text, x, y)
+  love.graphics.pop()
+end
+
+function system:draw()
+  for _, e in ipairs(self.pool) do
+    local x = e[c_button.dict.collider].data.x
+    local y = e[c_button.dict.collider].data.y
+    local w = e[c_button.dict.collider].data.w
+    local h = e[c_button.dict.collider].data.h
+    local label = e[c_button.dict.label].data
+    draw(label, x, y, w, h)
+  end
+end
+
+return system
diff --git a/game/src/world/common/template/button.lua b/game/src/world/common/template/button.lua
new file mode 100644
index 0000000..8c19399
--- /dev/null
+++ b/game/src/world/common/template/button.lua
@@ -0,0 +1,24 @@
+local button = require("src.world.common.component.button")
+
+local template = {}
+
+local function  default()
+end
+
+template.default_data = {
+  collider = {
+    x = 0,
+    y = 0,
+    w = 20,
+    h = 20
+  },
+  func = default,
+  label = "debug"
+}
+function template.assemble(e, data)
+  e:give(button.dict.collider, data.collider.x, data.collider.y, data.collider.w, data.collider.h)
+  e:give(button.dict.func, data.func)
+  e:give(button.dict.label, data.label)
+end
+
+return template
diff --git a/game/src/world/main_menu/init.lua b/game/src/world/main_menu/init.lua
new file mode 100644
index 0000000..392863c
--- /dev/null
+++ b/game/src/world/main_menu/init.lua
@@ -0,0 +1,47 @@
+local reap = require("lib.reap")
+
+local BASE = reap.base_path(...)
+
+local world = require("wrapper.Concord.world")
+
+local debug_entity = require("src.world.common.template.debug_entity")
+local button = require("src.world.common.template.button")
+
+local wrapper = world:extend()
+
+local function button_func()
+  load_world("race")
+end
+
+function wrapper:new()
+  wrapper.super.new(self, BASE, ".main_menu")
+end
+
+function wrapper:load(_args)
+  wrapper.super.load(self, {
+    "src/world/common/system/"
+  }, {
+    {
+      assemblage = debug_entity.assembleDebug,
+      data = {
+        position = {0, 0},
+        label = "main_menu"
+      }
+    },
+    {
+      assemblage = button.assemble,
+      data = {
+        collider = {
+          x = 20,
+          y = 20,
+          w = 20,
+          h = 20
+        },
+        func = button_func,
+        label = "race"
+      }
+    }
+  })
+end
+
+return wrapper