diff --git a/event.go b/event.go
index 8495301c..30ebafbd 100644
--- a/event.go
+++ b/event.go
@@ -89,23 +89,23 @@ func (p *eventSink) call(wait bool, data interface{}, doSth func(*eventSink)) {
 // -------------------------------------------------------------------------------------
 
 type eventSinkMgr struct {
-	allWhenStart      *eventSink
-	allWhenKeyPressed *eventSink
-	allWhenIReceive   *eventSink
-	allWhenSceneStart *eventSink
-	allWhenCloned     *eventSink
-	allWhenTouched    *eventSink
-	allWhenClick      *eventSink
-	allWhenMoving     *eventSink
-	allWhenTurning    *eventSink
-	calledStart       bool
+	allWhenStart           *eventSink
+	allWhenKeyPressed      *eventSink
+	allWhenIReceive        *eventSink
+	allWhenBackdropChanged *eventSink
+	allWhenCloned          *eventSink
+	allWhenTouched         *eventSink
+	allWhenClick           *eventSink
+	allWhenMoving          *eventSink
+	allWhenTurning         *eventSink
+	calledStart            bool
 }
 
 func (p *eventSinkMgr) reset() {
 	p.allWhenStart = nil
 	p.allWhenKeyPressed = nil
 	p.allWhenIReceive = nil
-	p.allWhenSceneStart = nil
+	p.allWhenBackdropChanged = nil
 	p.allWhenCloned = nil
 	p.allWhenTouched = nil
 	p.allWhenClick = nil
@@ -118,7 +118,7 @@ func (p *eventSinkMgr) doDeleteClone(this interface{}) {
 	p.allWhenStart = p.allWhenStart.doDeleteClone(this)
 	p.allWhenKeyPressed = p.allWhenKeyPressed.doDeleteClone(this)
 	p.allWhenIReceive = p.allWhenIReceive.doDeleteClone(this)
-	p.allWhenSceneStart = p.allWhenSceneStart.doDeleteClone(this)
+	p.allWhenBackdropChanged = p.allWhenBackdropChanged.doDeleteClone(this)
 	p.allWhenCloned = p.allWhenCloned.doDeleteClone(this)
 	p.allWhenTouched = p.allWhenTouched.doDeleteClone(this)
 	p.allWhenClick = p.allWhenClick.doDeleteClone(this)
@@ -189,8 +189,8 @@ func (p *eventSinkMgr) doWhenIReceive(msg string, data interface{}, wait bool) {
 	})
 }
 
-func (p *eventSinkMgr) doWhenSceneStart(name string, wait bool) {
-	p.allWhenSceneStart.call(wait, name, func(ev *eventSink) {
+func (p *eventSinkMgr) doWhenBackdropChanged(name string, wait bool) {
+	p.allWhenBackdropChanged.call(wait, name, func(ev *eventSink) {
 		ev.sink.(func(string))(name)
 	})
 }
@@ -324,23 +324,23 @@ func (p *eventSinks) OnMsg__1(msg string, onMsg func()) {
 	}
 }
 
-func (p *eventSinks) OnScene__0(onScene func(name string)) {
-	p.allWhenSceneStart = &eventSink{
-		prev:  p.allWhenSceneStart,
+func (p *eventSinks) OnBackdrop__0(onBackdrop func(name string)) {
+	p.allWhenBackdropChanged = &eventSink{
+		prev:  p.allWhenBackdropChanged,
 		pthis: p.pthis,
-		sink:  onScene,
+		sink:  onBackdrop,
 	}
 }
 
-func (p *eventSinks) OnScene__1(name string, onScene func()) {
-	p.allWhenSceneStart = &eventSink{
-		prev:  p.allWhenSceneStart,
+func (p *eventSinks) OnBackdrop__1(name string, onBackdrop func()) {
+	p.allWhenBackdropChanged = &eventSink{
+		prev:  p.allWhenBackdropChanged,
 		pthis: p.pthis,
 		sink: func(name string) {
 			if debugEvent {
-				log.Println("==> onScene", name, nameOf(p.pthis))
+				log.Println("==> onBackdrop", name, nameOf(p.pthis))
 			}
-			onScene()
+			onBackdrop()
 		},
 		cond: func(data interface{}) bool {
 			return data.(string) == name
diff --git a/game.go b/game.go
index 4a444fc2..1e50e6c0 100644
--- a/game.go
+++ b/game.go
@@ -1066,33 +1066,34 @@ func (p *Game) onHit(hc hitContext) (hr hitResult, ok bool) {
 
 // -----------------------------------------------------------------------------
 
-func (p *Game) SceneName() string {
+func (p *Game) BackdropName() string {
 	return p.getCostumeName()
 }
 
-func (p *Game) SceneIndex() int {
+func (p *Game) BackdropIndex() int {
 	return p.getCostumeIndex()
 }
 
-// StartScene func:
+// StartBackdrop func:
 //
-//	StartScene(sceneName) or
-//	StartScene(sceneIndex) or
-//	StartScene(spx.Next)
-//	StartScene(spx.Prev)
-func (p *Game) StartScene(scene interface{}, wait ...bool) {
-	if p.goSetCostume(scene) {
-		p.windowWidth_ = 0 // TODO: need review
-		p.doWhenSceneStart(p.getCostumeName(), wait != nil && wait[0])
+//	StartBackdrop(backdropName) or
+//	StartBackdrop(backdropIndex) or
+//	StartBackdrop(spx.Next)
+//	StartBackdrop(spx.Prev)
+func (p *Game) StartBackdrop(backdrop interface{}, wait ...bool) {
+	if p.goSetCostume(backdrop) {
+		p.windowWidth_ = 0
+		p.doWindowSize()
+		p.doWhenBackdropChanged(p.getCostumeName(), wait != nil && wait[0])
 	}
 }
 
-func (p *Game) NextScene(wait ...bool) {
-	p.StartScene(Next, wait...)
+func (p *Game) NextBackdrop(wait ...bool) {
+	p.StartBackdrop(Next, wait...)
 }
 
-func (p *Game) PrevScene(wait ...bool) {
-	p.StartScene(Prev, wait...)
+func (p *Game) PrevBackdrop(wait ...bool) {
+	p.StartBackdrop(Prev, wait...)
 }
 
 // -----------------------------------------------------------------------------
diff --git a/test/Bullet/assets/index.json b/test/Bullet/assets/index.json
index 287a7156..9f664708 100644
--- a/test/Bullet/assets/index.json
+++ b/test/Bullet/assets/index.json
@@ -6,7 +6,7 @@
       "path": "1.png"
     }
   ],
-  "sceneIndex": 0,
+  "backdropIndex": 0,
   "zorder": [
     "Bullet"
   ]