===================================================================
--- original.js
+++ change.js
@@ -546,11 +546,14 @@
 			var newB = (invB + Math.floor((0xFF - invB) * factor)) * Math.pow(16, 0);
 			playerGraphics.tint = newR + newG + newB;
 		}
 		if (targetDirection) {
-			var moveSpeed = Math.min(targetX + self.x * targetDirection, PLAYER_MOVE_SPEED);
+			var moveSpeed = Math.min((targetX - self.x) * targetDirection, PLAYER_MOVE_SPEED);
 			self.x += moveSpeed * targetDirection;
 			playerGraphics.rotation = Math.PI * (column.index + self.x / BOX_WIDTH);
+			if (moveSpeed < PLAYER_MOVE_SPEED) {
+				targetDirection = 0;
+			}
 		}
 		if (self.airborne) {
 			verticalSpeed -= PLAYER_GRAVITY;
 			self.y -= verticalSpeed;
@@ -569,42 +572,34 @@
 			} else {
 				self.y = targetY;
 			}
 		}
+		var rowIndex = getRowIndex();
 		var overhang = Math.max(0, Math.abs(self.x) - BOX_WIDTH / 2);
 		if (overhang > 0) {
 			var newColumn = columnList[column.index + targetDirection];
-			var newRowIndex = getRowIndex();
-			var sideBox = newColumn.boxes[newRowIndex];
+			var sideBox = newColumn ? newColumn.boxes[rowIndex] : null;
 			var moveDist = BOX_WIDTH * targetDirection;
 			if (sideBox && !sideBox.falling) {
 				sideBox.touch(self);
 				self.x -= overhang * 2 * targetDirection;
-				targetX -= moveDist;
+				targetX += moveDist;
 				targetDirection = -targetDirection;
 				playerGraphics.rotation = Math.PI * (column.index + self.x / BOX_WIDTH);
 			} else {
-				newColumn.enter(self);
-				targetX += moveDist;
-				self.x += moveDist;
-				var underBox = newColumn.boxes[newRowIndex - 1];
+				column = newColumn;
+				column.enter(self);
+				targetX -= moveDist;
+				self.x -= moveDist;
+				var underBox = column.boxes[rowIndex - 1];
 				if (!underBox || underBox.falling) {
 					self.airborne = true;
 				}
 			}
 		}
-		if (!self.airborne) {
-			var prevHeightIndex = Math.round(self.heightClimbed / BOX_HEIGHT);
-			columnList[newColIndex].touch(self, newRowIndex - 1);
-			if (newRowIndex > prevHeightIndex) {
-				interface.increment((newRowIndex - prevHeightIndex) * POINTS_GAIN_CLIMBING);
-				self.heightClimbed = newRowIndex * BOX_HEIGHT;
-				if (newRowIndex >= SHIFT_THRESHOLD) {
-					return true;
-				}
-			}
-		}
-		return false;
+		;
+		;
+		;
 	}
 	function shift(amount) {
 		baseShift(amount);
 		;