diff --git a/example/blocks/blocks/field.go b/example/blocks/blocks/field.go
index 2f002aa28..b9f5ff16f 100644
--- a/example/blocks/blocks/field.go
+++ b/example/blocks/blocks/field.go
@@ -79,6 +79,13 @@ func (f *Field) RotatePieceRight(piece *Piece, x, y int, angle Angle) Angle {
 	return angle.RotateRight()
 }
 
+func (f *Field) RotatePieceLeft(piece *Piece, x, y int, angle Angle) Angle {
+	if f.collides(piece, x, y, angle.RotateLeft()) {
+		return angle
+	}
+	return angle.RotateLeft()
+}
+
 func (f *Field) AbsorbPiece(piece *Piece, x, y int, angle Angle) {
 	piece.AbsorbInto(f, x, y, angle)
 	if f.flushable() {
diff --git a/example/blocks/blocks/gamescene.go b/example/blocks/blocks/gamescene.go
index d8c89441c..0830860b8 100644
--- a/example/blocks/blocks/gamescene.go
+++ b/example/blocks/blocks/gamescene.go
@@ -274,10 +274,14 @@ func (s *GameScene) Update(state *GameState) error {
 		piece := s.currentPiece
 		x := s.currentPieceX
 		y := s.currentPieceY
-		if state.Input.StateForKey(ebiten.KeySpace) == 1 {
+		if state.Input.StateForKey(ebiten.KeySpace) == 1 || state.Input.StateForKey(ebiten.KeyX) == 1 {
 			s.currentPieceAngle = s.field.RotatePieceRight(piece, x, y, angle)
 			moved = angle != s.currentPieceAngle
 		}
+		if state.Input.StateForKey(ebiten.KeyZ) == 1 {
+			s.currentPieceAngle = s.field.RotatePieceLeft(piece, x, y, angle)
+			moved = angle != s.currentPieceAngle
+		}
 		if l := state.Input.StateForKey(ebiten.KeyLeft); l == 1 || (10 <= l && l%2 == 0) {
 			s.currentPieceX = s.field.MovePieceToLeft(piece, x, y, angle)
 			moved = x != s.currentPieceX
diff --git a/example/blocks/blocks/piece.go b/example/blocks/blocks/piece.go
index 26d02effe..d9a6fc575 100644
--- a/example/blocks/blocks/piece.go
+++ b/example/blocks/blocks/piece.go
@@ -45,6 +45,13 @@ func (a Angle) RotateRight() Angle {
 	return a + 1
 }
 
+func (a Angle) RotateLeft() Angle {
+	if a == Angle0 {
+		return Angle270
+	}
+	return a - 1
+}
+
 type BlockType int
 
 const (