It's awesome!

robotgame/boulder.py

@@ -27,21 +27,30 @@ A rolling boulder.
 import pygame
 
 import worldobject
+import block
 
 class Boulder(worldobject.WorldObject):
-    def __init__(self, level, x, y, movable=True, rolling=True):
+    def __init__(self, level, x, y, movable=True, rolling=False):
         self.__dict__.update(locals())
         worldobject.WorldObject.__init__(self, level, x, y,
-                                         movable=movable, speed=1)
+                                         movable=movable, speed=4)
 
         self.anim = 'boulder_right'
         self.frame = 0
         self.anim_speed = 30
 
+    def activate(self, setting):
+        self.rolling = True
+
+    def reset_pos(self):
+        worldobject.WorldObject.reset_pos(self)
+        self.rolling = False
+
     def update(self, e, t, dt):
         # Update the animation
-        self.frame = ((self.frame + self.anim_speed * dt) %
-                      len(self.level.imgs[self.anim]))
+        if self.rolling:
+            self.frame = ((self.frame + self.anim_speed * dt) %
+                          len(self.level.imgs[self.anim]))
 
         if self.direction == (1, 0):
             self.anim = 'boulder_right'
@@ -52,7 +61,13 @@ class Boulder(worldobject.WorldObject):
         if self.direction == (0, -1):
             self.anim = 'boulder_up'
 
-        self.move(*self.direction)
+        tile_sharer = self.share_tile(block.ArrowBlock)
+        if tile_sharer:
+            self.direction = tile_sharer.direction
+
+        if self.rolling:
+            if not self.move(*self.direction) and not self.is_moving:
+                self.reset_pos()
 
         worldobject.WorldObject.update(self, e, t, dt)