diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,82 +1,9 @@
-{-# LANGUAGE DeriveFunctor #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE TupleSections #-}
-{-# LANGUAGE RecordWildCards #-}
 module Main where
 
-import Control.Concurrent (forkIO, threadDelay)
-import Control.Concurrent.STM.TVar
-import Control.Concurrent.STM.TBChan
-import Control.Lens hiding (argument)
-import Control.Monad (forever)
-import Control.Monad.STM (atomically)
-import Data.Char (chr)
-import Data.Foldable (for_)
-import qualified Data.Map as Map
-import Data.Semigroup ((<>))
-import Game.Tetris
-import Graphics.Vty
-import Linear.V2 (V2(..))
-import Prelude hiding (Left, Right)
-import Options.Applicative hiding ((<|>))
-
-versionOption :: Parser (a -> a)
-versionOption = infoOption "0.1.0.2" (long "version" <> help "Show version")
-
-data Options = Options { initialDelay :: Int } deriving Eq
-
-programOptions :: Parser Options
-programOptions =
-  Options <$> option auto (long "initial-delay" <> metavar "MICROSECONDS" <>
-                           value 1000000 <> showDefault <>
-                           help "Initial delay")
-
-data Event e = Tick | Ev e deriving (Eq, Read, Show, Functor)
-
-main = do
-  Options {..} <- execParser $
-    info (helper <*> versionOption <*> programOptions)
-         (fullDesc <> progDesc "Braille Tetris")
-  vty <- mkVty defaultConfig
-  chan <- atomically $ newTBChan 10
-  game <- initGame 0
-  speed <- newTVarIO initialDelay
-
-  forkIO $ forever $ do
-    e <- nextEvent vty
-    atomically $ writeTBChan chan $ Ev e
-
-  forkIO $ forever $ do
-    atomically $ writeTBChan chan Tick
-    delay <- readTVarIO speed
-    atomically $ modifyTVar speed ((-) 100)
-    threadDelay delay
-
-  consume vty chan game
-
-  shutdown vty
-
-consume vty chan game = if isGameOver game then pure () else do
-  update vty $ picForImage $
-   string defAttr (emboss game) <|> string defAttr (show $ game ^. score)
-  e <- atomically $ readTBChan chan
-  case e of
-    Ev (EvKey KEsc []) -> pure ()
-    Tick -> timeStep game >>= consume vty chan
-    Ev (EvKey KLeft []) -> consume vty chan (hardDrop game)
-    Ev (EvKey KUp []) -> consume vty chan (shift Left game)
-    Ev (EvKey KDown []) -> consume vty chan (shift Right game)
-    Ev (EvKey KEnter []) -> consume vty chan (rotate game)
-    _ -> consume vty chan game
+import qualified Command.Betris as Betris
+import Control.Monad (join)
+import Options.Applicative
 
-emboss :: Game -> String
-emboss g = map go [1, 3 .. boardHeight] where
-  go y = chr $ foldr (f y) 0x2800 [((0,0),1), ((1,0), 2), ((2,0), 4)
-                                  ,((0,1),8), ((1,1),16), ((2,1),32)
-                                  ,((3,0),64),((3,1),128)]
-  f y ((x',y'), v) a = case Map.lookup (V2 (x+x') (y+y')) fullBoard of
-    Just _ -> a + v
-    _ -> a
-  x = minimum $ (boardWidth - 3) : map (\(V2 x _) -> x) (coords $ g ^. block)
-  fullBoard = g ^. board <> blk (g ^. block)
-  blk b = Map.fromList $ map (, b ^. shape) $ coords b
+main = join $ execParser $ info (helper <*> Betris.command) $
+    fullDesc
+ <> progDesc "Braille Tetris"
diff --git a/betris.cabal b/betris.cabal
--- a/betris.cabal
+++ b/betris.cabal
@@ -2,11 +2,11 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 5360efc32ccffdd515059c6e1e560a8654006da8d9f4bf594d7712a8f739cd92
+-- hash: fe3279b316adac9c02a50ad90f46dd1800c4189084639dd9ff3b91c81847dc20
 
 name:           betris
-version:        0.1.0.2
-synopsis:       Braille friendly horizontal version of tetris
+version:        0.1.1.0
+synopsis:       A horizontal version of tetris for braille users
 description:    Please see the README at <https://github.com/mlang/betris#readme>
 category:       Game
 homepage:       https://github.com/mlang/betris#readme
@@ -27,21 +27,23 @@
 
 library
   exposed-modules:
+      Command.Betris
       Game.Tetris
   other-modules:
       Paths_betris
   hs-source-dirs:
       src
   build-depends:
-      base >=4.7 && <5
-    , containers
-    , lens
-    , linear
-    , optparse-applicative
-    , random
-    , stm
-    , stm-chans
-    , vty
+      base >=4.11.0 && <4.12
+    , containers >=0.5.7 && <0.6
+    , lens >=4.16.0 && <4.17
+    , linear >=1.20.7 && <1.21
+    , optparse-applicative >=0.14.2 && <0.15
+    , random >=1.1 && <1.2
+    , stm >=2.4.5 && <2.5
+    , stm-chans >=3.0.0 && <3.1
+    , time-units >=1.0.0 && <1.1
+    , vty >=5.21 && <5.24
   default-language: Haskell2010
 
 executable betris
@@ -52,14 +54,15 @@
       app
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
   build-depends:
-      base >=4.7 && <5
+      base >=4.11.0 && <4.12
     , betris
-    , containers
-    , lens
-    , linear
-    , optparse-applicative
-    , random
-    , stm
-    , stm-chans
-    , vty
+    , containers >=0.5.7 && <0.6
+    , lens >=4.16.0 && <4.17
+    , linear >=1.20.7 && <1.21
+    , optparse-applicative >=0.14.2 && <0.15
+    , random >=1.1 && <1.2
+    , stm >=2.4.5 && <2.5
+    , stm-chans >=3.0.0 && <3.1
+    , time-units >=1.0.0 && <1.1
+    , vty >=5.21 && <5.24
   default-language: Haskell2010
diff --git a/src/Command/Betris.hs b/src/Command/Betris.hs
new file mode 100644
--- /dev/null
+++ b/src/Command/Betris.hs
@@ -0,0 +1,88 @@
+{-# LANGUAGE DeriveFunctor #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE RecordWildCards #-}
+module Command.Betris (command, Options(..), betris) where
+
+import Control.Concurrent (forkIO, threadDelay)
+import Control.Concurrent.STM.TVar
+import Control.Concurrent.STM.TBChan
+import Control.Lens hiding (argument)
+import Control.Monad (forever)
+import Control.Monad.STM (atomically)
+import Data.Char (chr)
+import Data.Foldable (for_)
+import qualified Data.Map as Map
+import Data.Time.Units
+import Data.Version (showVersion)
+import Game.Tetris
+import Graphics.Vty
+import Linear.V2 (V2(..))
+import Paths_betris (version)
+import Prelude hiding (Left, Right)
+import Options.Applicative hiding (command, (<|>))
+
+command :: Parser (IO ())
+command = betris <$> (versionOption <*> programOptions)
+
+data Options = Options { initialDelay :: Millisecond } deriving (Eq, Show)
+
+programOptions :: Parser Options
+programOptions =
+  Options <$> option auto (long "initial-delay" <> metavar "DURATION" <>
+                           value (fromMicroseconds 1000000) <> showDefault <>
+                           help "Initial delay")
+
+data Event e = Tick | Ev e deriving (Eq, Read, Show, Functor)
+
+betris Options{..} = do
+  vty <- mkVty =<< userConfig
+  chan <- newTBChanIO 10
+  game <- initGame 0
+  speed <- newTVarIO $ fromIntegral $ toMicroseconds initialDelay
+
+  forkIO $ forever $ do
+    e <- nextEvent vty
+    atomically $ writeTBChan chan $ Ev e
+
+  forkIO $ forever $ do
+    atomically $ writeTBChan chan Tick
+    delay <- readTVarIO speed
+    atomically $ modifyTVar speed ((-) 500)
+    threadDelay delay
+
+  _ <- play vty chan game
+  shutdown vty
+  putStrLn ""
+
+play vty chan game
+  | isGameOver game = pure $ game ^. score
+  | otherwise = do
+    update vty $ picForImage $
+      string defAttr (emboss game) <|> string defAttr (show $ game ^. score)
+    e <- atomically $ readTBChan chan
+    case e of
+      Ev (EvKey KEsc []) -> pure $ game ^. score
+      Tick -> timeStep game >>= play vty chan
+      Ev (EvKey KLeft []) -> play vty chan (hardDrop game)
+      Ev (EvKey KUp []) -> play vty chan (shift Left game)
+      Ev (EvKey KDown []) -> play vty chan (shift Right game)
+      Ev (EvKey KEnter []) -> play vty chan (rotate game)
+      _ -> play vty chan game
+
+emboss :: Game -> String
+emboss g = map go [1, 3 .. boardHeight] where
+  go y = chr $ foldr (f y) 0x2800 [((0,0),1), ((1,0), 2), ((2,0), 4)
+                                  ,((0,1),8), ((1,1),16), ((2,1),32)
+                                  ,((3,0),64),((3,1),128)]
+  f y ((x',y'), v) a = case Map.lookup (V2 (x+x') (y+y')) fullBoard of
+    Just _ -> a + v
+    _ -> a
+  x = minimum $ (boardWidth - 3) : map (\(V2 x _) -> x) (coords $ g ^. block)
+  fullBoard = g ^. board <> blk (g ^. block)
+  blk b = Map.fromList $ map (, b ^. shape) $ coords b
+
+versionOption :: Parser (a -> a)
+versionOption = infoOption (showVersion version) $
+    long "version"
+ <> help "Show version"
diff --git a/src/Game/Tetris.hs b/src/Game/Tetris.hs
--- a/src/Game/Tetris.hs
+++ b/src/Game/Tetris.hs
@@ -143,7 +143,7 @@
   where
     go (t :< ts) = pure (t, ts)
     go EmptyL = freshList >>= bagFourTetriminoEach
-    freshList = shuffle . Seq.fromList . take 28 . cycle $ [I ..]
+    freshList = shuffle . Seq.fromList . take 28 . cycle $ [(I)..]
 
 -- | Initialize a game with a given level
 initGame :: Int ->  IO Game