diff --git a/slacker_game/__init__.py b/slacker_game/__init__.py
index 2d06f48..cad20d8 100644
--- a/slacker_game/__init__.py
+++ b/slacker_game/__init__.py
@@ -17,8 +17,7 @@
 
 """A clone of the arcade game Stacker"""
 
-__version__ = '2.1.0'
-__all__ = ['Slacker']
+from __future__ import annotations
 
 from contextlib import ExitStack, redirect_stdout
 from importlib.resources import path
@@ -35,6 +34,8 @@ from pygame.font import Font
 from pygame.surface import Surface
 from pygame.time import get_ticks
 
+__version__ = '2.1.1'
+
 TANGO = {'Butter': ((252, 233, 79), (237, 212, 0), (196, 160, 0)),
          'Orange': ((252, 175, 62), (245, 121, 0), (206, 92, 0)),
          'Chocolate': ((233, 185, 110), (193, 125, 17), (143, 89, 2)),
@@ -82,8 +83,10 @@ class SlackerTile:
         self.wiggle = state in (INTRO, WIN)
 
     def get_xoffset(self, maxoffset: float, duration: int = 820) -> float:
-        """Return the offset on x-axis to make the tile complete an cycle of
-        wiggling oscillation in given duration (in milliseconds).
+        """Return the offset on x-axis for wiggling oscillation.
+
+        The oscillation's cycle can be specified
+        in milliseconds as duration.
         """
         if not self.wiggle: return 0
         return maxoffset * cos((get_ticks()/duration+self.y/BOARD_HEIGHT)*pi)
@@ -111,9 +114,7 @@ class SlackerTile:
 
 
 class Slacker:
-    """This class provides functions to run the game Slacker, a clone of
-    the popular arcade game Stacker.
-    """
+    """Game object."""
 
     def __init__(self, restart: bool = False) -> None:
         self.exit_stack = ExitStack()
@@ -191,20 +192,22 @@ class Slacker:
                               for x in range(BOARD_WIDTH)]
 
     def key_hit(self) -> None:
-        """Process the current position of the blocks relatively to the
-        ones underneath when user hit the switch, then decide if the
-        user will win, lose or go to the next level of the tower.
+        """Handle block-stacking event.
+
+        Process the current position of the blocks, relative to the ones
+        underneath when user hit the switch, then decide if the user
+        will win, lose or go to the next level of the tower.
         """
         if self.y < BOARD_HEIGHT - 1:
             for x in range(max(0, self.x),
-                           min(self.x + self.width, BOARD_WIDTH)):
-                # If there isn't any block underneath
-                if not self.board[self.y + 1][x]:
-                    # Get rid of the block not standing on solid ground
-                    self.board[self.y][x] = False
-                    # Then, add that falling block to falling_tiles
-                    self.falling_tiles.append(SlackerTile(
-                        self.screen, x, self.y, missed_time=get_ticks()))
+                           min(self.x+self.width, BOARD_WIDTH)):
+                if self.board[self.y + 1][x]: continue
+                # If there isn't any block underneath,
+                # get rid of the block not standing on solid ground
+                self.board[self.y][x] = False
+                # Then, add that falling block to falling_tiles
+                self.falling_tiles.append(SlackerTile(
+                    self.screen, x, self.y, missed_time=get_ticks()))
         self.width = sum(self.board[self.y])
         if not self.width:
             self.game_state = LOSE
diff --git a/tox.ini b/tox.ini
index d000d25..adefae6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,9 @@ commands =
     mypy slacker_game
 
 [flake8]
+hang-closing = True
 ignore = E226, E701, E704, W503
+max-doc-length = 72
 
 [isort]
 balanced_wrapping = True