diff --git a/app/scenes/cube_tube.rb b/app/scenes/cube_tube.rb
index 67fef63..bbbbeb6 100644
--- a/app/scenes/cube_tube.rb
+++ b/app/scenes/cube_tube.rb
@@ -34,15 +34,15 @@ class BlockTubeGame
     ]
 
     @sprite_index = [
-      "sprites/square/black.png",
-      "sprites/square/red.png",
-      "sprites/square/green.png",
-      "sprites/square/blue.png",
-      "sprites/square/yellow.png",
-      "sprites/square/indigo.png",
-      "sprites/square/violet.png",
-      "sprites/square/orange.png",
-      "sprites/square/gray.png",
+      Sprite.for(:black),
+      Sprite.for(:red),
+      Sprite.for(:green),
+      Sprite.for(:blue),
+      Sprite.for(:yellow),
+      Sprite.for(:indigo),
+      Sprite.for(:violet),
+      Sprite.for(:orange),
+      Sprite.for(:gray)
     ]
 
     @grid = []
diff --git a/app/sprite.rb b/app/sprite.rb
index 4648aab..7304bde 100644
--- a/app/sprite.rb
+++ b/app/sprite.rb
@@ -2,14 +2,24 @@ module Sprite
   # annoying to track but useful for reloading with +i+ in debug mode; would be
   # nice to define a different way
   SPRITES = {
-    bullet: "sprites/bullet.png",
-    enemy: "sprites/enemy.png",
-    enemy_king: "sprites/enemy_king.png",
-    enemy_super: "sprites/enemy_super.png",
-    exp_chip: "sprites/exp_chip.png",
-    familiar: "sprites/familiar.png",
-    player: "sprites/player.png",
-    pause: "sprites/pause.png",
+    bullet: 'sprites/bullet.png',
+    enemy: 'sprites/enemy.png',
+    enemy_king: 'sprites/enemy_king.png',
+    enemy_super: 'sprites/enemy_super.png',
+    exp_chip: 'sprites/exp_chip.png',
+    familiar: 'sprites/familiar.png',
+    player: 'sprites/player.png',
+    pause: 'sprites/pause.png',
+    gray: 'sprites/square/gray.png',
+    black: 'sprites/square/black.png',
+    white: 'sprites/square/white.png',
+    red: 'sprites/square/red.png',
+    green: 'sprites/square/green.png',
+    blue: 'sprites/square/blue.png',
+    yellow: 'sprites/square/yellow.png',
+    indigo: 'sprites/square/indigo.png',
+    violet: 'sprites/square/violet.png',
+    orange: 'sprites/square/orange.png'
   }
 
   class << self