diff --git a/examples/blocks/blocks/gamepad.go b/examples/blocks/blocks/gamepad.go
index 43f0a3917..a5214742e 100644
--- a/examples/blocks/blocks/gamepad.go
+++ b/examples/blocks/blocks/gamepad.go
@@ -124,6 +124,8 @@ func (c *gamepadConfig) Scan(gamepadID int, b virtualGamepadButton) bool {
 	return false
 }
 
+// IsButtonPressed returns a boolean value indicating whether
+// the given virtual button b is pressed.
 func (c *gamepadConfig) IsButtonPressed(b virtualGamepadButton) bool {
 	c.initializeIfNeeded()
 
@@ -131,6 +133,7 @@ func (c *gamepadConfig) IsButtonPressed(b virtualGamepadButton) bool {
 	if ok {
 		return ebiten.IsGamepadButtonPressed(0, bb)
 	}
+
 	a, ok := c.axes[b]
 	if ok {
 		v := ebiten.GamepadAxis(0, a.id)
@@ -143,7 +146,7 @@ func (c *gamepadConfig) IsButtonPressed(b virtualGamepadButton) bool {
 	return false
 }
 
-// Name returns the button's name.
+// Name returns the pysical button's name for the given virtual button.
 func (c *gamepadConfig) ButtonName(b virtualGamepadButton) string {
 	c.initializeIfNeeded()
 
diff --git a/examples/blocks/blocks/input.go b/examples/blocks/blocks/input.go
index 3e3cd24e0..6e487df49 100644
--- a/examples/blocks/blocks/input.go
+++ b/examples/blocks/blocks/input.go
@@ -20,6 +20,7 @@ import (
 	"github.com/hajimehoshi/ebiten"
 )
 
+// Input manages the input state including gamepads and keyboards.
 type Input struct {
 	keyStates                  map[ebiten.Key]int
 	anyGamepadButtonPressed    bool
@@ -27,6 +28,7 @@ type Input struct {
 	gamepadConfig              gamepadConfig
 }
 
+// StateForKey returns time length indicating how long the key is pressed.
 func (i *Input) StateForKey(key ebiten.Key) int {
 	if i.keyStates == nil {
 		return 0
@@ -34,6 +36,8 @@ func (i *Input) StateForKey(key ebiten.Key) int {
 	return i.keyStates[key]
 }
 
+// IsAnyGamepadButtonPressed returns a boolean value indicating
+// whether any gamepad button is pressed.
 func (i *Input) IsAnyGamepadButtonPressed() bool {
 	return i.anyGamepadButtonPressed
 }