diff --git a/camera.go b/camera.go
index 7f49ec1b..82a33f97 100644
--- a/camera.go
+++ b/camera.go
@@ -59,9 +59,9 @@ func (c *Camera) worldToScreen(point *math32.Vector2) *math32.Vector2 {
 }
 */
 
-func (c *Camera) On(obj interface{}) {
+func (c *Camera) on(obj interface{}) {
 	switch v := obj.(type) {
-	case string:
+	case SpriteName:
 		sp := c.g.findSprite(v)
 		if sp == nil {
 			log.Println("Camera.On: sprite not found -", v)
@@ -83,6 +83,22 @@ func (c *Camera) On(obj interface{}) {
 	c.on_ = obj
 }
 
+func (c *Camera) On__0(sprite Sprite) {
+	c.on(sprite)
+}
+
+func (c *Camera) On__1(sprite *SpriteImpl) {
+	c.on(sprite)
+}
+
+func (c *Camera) On__2(sprite SpriteName) {
+	c.on(sprite)
+}
+
+func (c *Camera) On__3(obj specialObj) {
+	c.on(obj)
+}
+
 func (c *Camera) updateOnObj() {
 	switch v := c.on_.(type) {
 	case *SpriteImpl:
diff --git a/event.go b/event.go
index 3a77da6e..e789bebc 100644
--- a/event.go
+++ b/event.go
@@ -213,17 +213,17 @@ func (p *eventSinkMgr) doWhenIReceive(msg string, data interface{}, wait bool) {
 	})
 }
 
-func (p *eventSinkMgr) doWhenBackdropChanged(name string, wait bool) {
+func (p *eventSinkMgr) doWhenBackdropChanged(name BackdropName, wait bool) {
 	p.allWhenBackdropChanged.call(wait, name, func(ev *eventSink) {
-		ev.sink.(func(string))(name)
+		ev.sink.(func(BackdropName))(name)
 	})
 }
 
 // -------------------------------------------------------------------------------------
 type IEventSinks interface {
 	OnAnyKey(onKey func(key Key))
-	OnBackdrop__0(onBackdrop func(name string))
-	OnBackdrop__1(name string, onBackdrop func())
+	OnBackdrop__0(onBackdrop func(name BackdropName))
+	OnBackdrop__1(name BackdropName, onBackdrop func())
 	OnClick(onClick func())
 	OnKey__0(key Key, onKey func())
 	OnKey__1(keys []Key, onKey func(Key))
@@ -361,7 +361,7 @@ func (p *eventSinks) OnMsg__1(msg string, onMsg func()) {
 	}
 }
 
-func (p *eventSinks) OnBackdrop__0(onBackdrop func(name string)) {
+func (p *eventSinks) OnBackdrop__0(onBackdrop func(name BackdropName)) {
 	p.allWhenBackdropChanged = &eventSink{
 		prev:  p.allWhenBackdropChanged,
 		pthis: p.pthis,
@@ -369,18 +369,18 @@ func (p *eventSinks) OnBackdrop__0(onBackdrop func(name string)) {
 	}
 }
 
-func (p *eventSinks) OnBackdrop__1(name string, onBackdrop func()) {
+func (p *eventSinks) OnBackdrop__1(name BackdropName, onBackdrop func()) {
 	p.allWhenBackdropChanged = &eventSink{
 		prev:  p.allWhenBackdropChanged,
 		pthis: p.pthis,
-		sink: func(name string) {
+		sink: func(name BackdropName) {
 			if debugEvent {
 				log.Println("==> onBackdrop", name, nameOf(p.pthis))
 			}
 			onBackdrop()
 		},
 		cond: func(data interface{}) bool {
-			return data.(string) == name
+			return data.(BackdropName) == name
 		},
 	}
 }
diff --git a/game.go b/game.go
index 0ee16967..8a569076 100644
--- a/game.go
+++ b/game.go
@@ -473,7 +473,7 @@ func (p *Game) loadIndex(g reflect.Value, proj *projConfig) (err error) {
 
 	ebiten.SetWindowResizingMode(ebiten.WindowResizingModeOnlyFullscreenEnabled)
 	if proj.Camera != nil && proj.Camera.On != "" {
-		p.Camera.On(proj.Camera.On)
+		p.Camera.On__2(proj.Camera.On)
 	}
 	if loader, ok := g.Addr().Interface().(interface{ OnLoaded() }); ok {
 		loader.OnLoaded()
@@ -860,7 +860,7 @@ func (p *Game) touchingSpriteBy(dst *SpriteImpl, name string) *SpriteImpl {
 
 func (p *Game) objectPos(obj interface{}) (float64, float64) {
 	switch v := obj.(type) {
-	case string:
+	case SpriteName:
 		if sp := p.findSprite(v); sp != nil {
 			return sp.getXY()
 		}
@@ -1033,7 +1033,7 @@ func (p *Game) doFindSprite(src Shape) int {
 	return -1
 }
 
-func (p *Game) findSprite(name string) *SpriteImpl {
+func (p *Game) findSprite(name SpriteName) *SpriteImpl {
 	for _, item := range p.items {
 		if sp, ok := item.(*SpriteImpl); ok {
 			if !sp.isCloned_ && sp.name == name {
@@ -1045,7 +1045,6 @@ func (p *Game) findSprite(name string) *SpriteImpl {
 }
 
 // -----------------------------------------------------------------------------
-
 func (p *Game) drawBackground(dc drawContext) {
 	c := p.costumes[p.costumeIndex_]
 	img, _, _ := c.needImage(p.fs)
@@ -1156,7 +1155,9 @@ func (p *Game) onHit(hc hitContext) (hr hitResult, ok bool) {
 
 // -----------------------------------------------------------------------------
 
-func (p *Game) BackdropName() string {
+type BackdropName = string
+
+func (p *Game) BackdropName() BackdropName {
 	return p.getCostumeName()
 }
 
@@ -1166,24 +1167,64 @@ func (p *Game) BackdropIndex() int {
 
 // StartBackdrop func:
 //
-//	StartBackdrop(backdropName) or
-//	StartBackdrop(backdropIndex) or
+//	StartBackdrop(backdrop) or
+//	StartBackdrop(index) or
 //	StartBackdrop(spx.Next)
 //	StartBackdrop(spx.Prev)
-func (p *Game) StartBackdrop(backdrop interface{}, wait ...bool) {
+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])
+		p.doWhenBackdropChanged(p.getCostumeName(), wait)
 	}
 }
 
-func (p *Game) NextBackdrop(wait ...bool) {
-	p.StartBackdrop(Next, wait...)
+func (p *Game) StartBackdrop__0(backdrop BackdropName) {
+	p.startBackdrop(backdrop, false)
+}
+
+func (p *Game) StartBackdrop__1(backdrop BackdropName, wait bool) {
+	p.startBackdrop(backdrop, wait)
+}
+
+func (p *Game) StartBackdrop__2(index int) {
+	p.startBackdrop(index, false)
+}
+
+func (p *Game) StartBackdrop__3(index int, wait bool) {
+	p.startBackdrop(index, wait)
+}
+
+func (p *Game) StartBackdrop__4(index float64) {
+	p.startBackdrop(index, false)
+}
+
+func (p *Game) StartBackdrop__5(index float64, wait bool) {
+	p.startBackdrop(index, wait)
 }
 
-func (p *Game) PrevBackdrop(wait ...bool) {
-	p.StartBackdrop(Prev, wait...)
+func (p *Game) StartBackdrop__6(action switchAction) {
+	p.startBackdrop(action, false)
+}
+
+func (p *Game) StartBackdrop__7(action switchAction, wait bool) {
+	p.startBackdrop(action, wait)
+}
+
+func (p *Game) NextBackdrop__0() {
+	p.StartBackdrop__6(Next)
+}
+
+func (p *Game) NextBackdrop__1(wait bool) {
+	p.StartBackdrop__7(Next, wait)
+}
+
+func (p *Game) PrevBackdrop__0() {
+	p.StartBackdrop__6(Prev)
+}
+
+func (p *Game) PrevBackdrop__1(wait bool) {
+	p.StartBackdrop__7(Prev, wait)
 }
 
 // -----------------------------------------------------------------------------
@@ -1282,6 +1323,8 @@ func (p *Game) ClearSoundEffects() {
 
 type Sound *soundConfig
 
+type SoundName = string
+
 func (p *Game) canBindSound(name string) bool {
 	// auto bind the sound, if assets/sounds/{name}/index.json exists.
 	prefix := "sounds/" + name
@@ -1293,7 +1336,7 @@ func (p *Game) canBindSound(name string) bool {
 	return true
 }
 
-func (p *Game) loadSound(name string) (media Sound, err error) {
+func (p *Game) loadSound(name SoundName) (media Sound, err error) {
 	if media, ok := p.sounds.audios[name]; ok {
 		return media, nil
 	}
@@ -1317,9 +1360,6 @@ func (p *Game) loadSound(name string) (media Sound, err error) {
 //	Play(video) -- maybe
 //	Play(media, wait) -- sync
 //	Play(media, opts)
-//	Play(mediaName)
-//	Play(mediaName, wait) -- sync
-//	Play(mediaName, opts)
 func (p *Game) Play__0(media Sound) {
 	p.Play__2(media, &PlayOptions{})
 }
@@ -1338,21 +1378,22 @@ func (p *Game) Play__2(media Sound, action *PlayOptions) {
 		panic(err)
 	}
 }
-func (p *Game) Play__3(mediaName string) {
-	p.Play__5(mediaName, &PlayOptions{})
+
+func (p *Game) Play__3(media SoundName) {
+	p.Play__5(media, &PlayOptions{})
 }
 
-func (p *Game) Play__4(mediaName string, wait bool) {
-	p.Play__5(mediaName, &PlayOptions{Wait: wait})
+func (p *Game) Play__4(media SoundName, wait bool) {
+	p.Play__5(media, &PlayOptions{Wait: wait})
 }
 
-func (p *Game) Play__5(mediaName string, action *PlayOptions) {
-	media, err := p.loadSound(mediaName)
+func (p *Game) Play__5(media SoundName, action *PlayOptions) {
+	m, err := p.loadSound(media)
 	if err != nil {
 		log.Println(err)
 		return
 	}
-	p.Play__2(media, action)
+	p.Play__2(m, action)
 }
 
 func (p *Game) StopAllSounds() {
@@ -1433,7 +1474,7 @@ type ShapeGetter interface {
 // Instead of being used directly, it is meant to be called by `Gopt_Game_Gopx_GetWidget` only.
 // We extract `GetWidget_` to keep `Gopt_Game_Gopx_GetWidget` simple, which simplifies work in ispx,
 // see details in https://github.com/goplus/builder/issues/765#issuecomment-2313915805.
-func GetWidget_(sg ShapeGetter, name string) Widget {
+func GetWidget_(sg ShapeGetter, name WidgetName) Widget {
 	items := sg.getAllShapes()
 	for _, item := range items {
 		widget, ok := item.(Widget)
@@ -1445,7 +1486,7 @@ func GetWidget_(sg ShapeGetter, name string) Widget {
 }
 
 // GetWidget returns the widget instance (in given type) with given name. It panics if not found.
-func Gopt_Game_Gopx_GetWidget[T any](sg ShapeGetter, name string) *T {
+func Gopt_Game_Gopx_GetWidget[T any](sg ShapeGetter, name WidgetName) *T {
 	widget := GetWidget_(sg, name)
 	if result, ok := widget.(interface{}).(*T); ok {
 		return result
diff --git a/monitor.go b/monitor.go
index c32a817e..c024f579 100644
--- a/monitor.go
+++ b/monitor.go
@@ -37,7 +37,7 @@ import (
 // Monitor class.
 type Monitor struct {
 	game    *Game
-	name    string
+	name    WidgetName
 	size    float64
 	target  string
 	val     string
@@ -304,7 +304,7 @@ func (p *Monitor) hit(hc hitContext) (hr hitResult, ok bool) {
 
 // -------------------------------------------------------------------------------------
 // IWidget
-func (pself *Monitor) GetName() string {
+func (pself *Monitor) GetName() WidgetName {
 	return pself.name
 }
 
diff --git a/spbase.go b/spbase.go
index 8e3c2574..b2dc2837 100644
--- a/spbase.go
+++ b/spbase.go
@@ -174,7 +174,7 @@ func (p *imageLoaderByCostumeSet) load(fs spxfs.Dir, pt *imagePoint) (gdi.Image,
 // -------------------------------------------------------------------------------------
 
 type costume struct {
-	name             string
+	name             SpriteCostumeName
 	img              delayloadImage
 	faceRight        float64
 	bitmapResolution int
@@ -296,7 +296,7 @@ func initCSPart(p *baseObj, img *costumeSetImage, faceRight float64, bitmapResol
 	}
 }
 
-func addCostumeWith(p *baseObj, name string, img *costumeSetImage, faceRight float64, i, bitmapResolution int) {
+func addCostumeWith(p *baseObj, name SpriteCostumeName, img *costumeSetImage, faceRight float64, i, bitmapResolution int) {
 	c := newCostumeWith(name, img, faceRight, i, bitmapResolution)
 	p.costumes = append(p.costumes, c)
 }
@@ -334,7 +334,7 @@ func (p *baseObj) initFrom(src *baseObj) {
 	p.costumeIndex_ = src.costumeIndex_
 }
 
-func (p *baseObj) findCostume(name string) int {
+func (p *baseObj) findCostume(name SpriteCostumeName) int {
 	for i, c := range p.costumes {
 		if c.name == name {
 			return i
@@ -345,7 +345,7 @@ func (p *baseObj) findCostume(name string) int {
 
 func (p *baseObj) goSetCostume(val interface{}) bool {
 	switch v := val.(type) {
-	case string:
+	case SpriteCostumeName:
 		return p.setCostumeByName(v)
 	case int:
 		return p.setCostumeByIndex(v)
@@ -373,8 +373,7 @@ func (p *baseObj) setCostumeByIndex(idx int) bool {
 	}
 	return false
 }
-
-func (p *baseObj) setCostumeByName(name string) bool {
+func (p *baseObj) setCostumeByName(name SpriteCostumeName) bool {
 	if idx := p.findCostume(name); idx >= 0 {
 		return p.setCostumeByIndex(idx)
 	}
@@ -393,7 +392,7 @@ func (p *baseObj) getCostumeIndex() int {
 	return p.costumeIndex_
 }
 
-func (p *baseObj) getCostumeName() string {
+func (p *baseObj) getCostumeName() SpriteCostumeName {
 	return p.costumes[p.costumeIndex_].name
 }
 
diff --git a/sprite.go b/sprite.go
index 337c1a71..4c25e4a5 100644
--- a/sprite.go
+++ b/sprite.go
@@ -111,7 +111,7 @@ type Sprite interface {
 	Shape
 	Main()
 
-	Animate(name string)
+	Animate(name SpriteAnimationName)
 	Ask(msg interface{})
 	BounceOffEdge()
 	Bounds() *math32.RotatedRect
@@ -128,16 +128,24 @@ type Sprite interface {
 	ClearGraphEffects()
 	CostumeHeight() float64
 	CostumeIndex() int
-	CostumeName() string
+	CostumeName() SpriteCostumeName
 	CostumeWidth() float64
 	DeleteThisClone()
 	Destroy()
 	Die()
-	DistanceTo(obj interface{}) float64
+	DistanceTo__0(sprite Sprite) float64
+	DistanceTo__1(sprite SpriteName) float64
+	DistanceTo__2(obj specialObj) float64
+	DistanceTo__3(pos Pos) float64
 	Glide__0(x, y float64, secs float64)
-	Glide__1(obj interface{}, secs float64)
+	Glide__1(sprite Sprite, secs float64)
+	Glide__2(sprite SpriteName, secs float64)
+	Glide__3(obj specialObj, secs float64)
+	Glide__4(pos Pos, secs float64)
 	GoBackLayers(n int)
-	Goto(obj interface{})
+	Goto__0(sprite Sprite)
+	Goto__1(sprite SpriteName)
+	Goto__2(obj specialObj)
 	GotoBack()
 	GotoFront()
 	Heading() float64
@@ -153,8 +161,8 @@ type Sprite interface {
 	OnMoving__1(onMoving func())
 	OnTouchStart__0(onTouchStart func(Sprite))
 	OnTouchStart__1(onTouchStart func())
-	OnTouchStart__2(name string, onTouchStart func(Sprite))
-	OnTouchStart__3(name string, onTouchStart func())
+	OnTouchStart__2(sprite SpriteName, onTouchStart func(Sprite))
+	OnTouchStart__3(sprite SpriteName, onTouchStart func())
 	OnTurning__0(onTurning func(ti *TurningInfo))
 	OnTurning__1(onTurning func())
 	Parent() *Game
@@ -163,9 +171,14 @@ type Sprite interface {
 	PrevCostume()
 	Quote__0(message string)
 	Quote__1(message string, secs float64)
-	Quote__2(message, description string, secs ...float64)
-	Say(msg interface{}, secs ...float64)
-	SetCostume(costume interface{})
+	Quote__2(message, description string)
+	Quote__3(message, description string, secs float64)
+	Say__0(msg interface{})
+	Say__1(msg interface{}, secs float64)
+	SetCostume__0(costume SpriteCostumeName)
+	SetCostume__1(index int)
+	SetCostume__2(index float64)
+	SetCostume__3(action switchAction)
 	SetDying()
 	SetEffect(kind EffectKind, val float64)
 	SetHeading(dir float64)
@@ -184,17 +197,32 @@ type Sprite interface {
 	Stamp()
 	Step__0(step float64)
 	Step__1(step int)
-	Step__2(step float64, animname string)
-	Think(msg interface{}, secs ...float64)
-	Touching(obj interface{}) bool
+	Step__2(step float64, animation SpriteAnimationName)
+	Think__0(msg interface{})
+	Think__1(msg interface{}, secs float64)
+	Touching__0(sprite SpriteName) bool
+	Touching__1(sprite Sprite) bool
+	Touching__2(obj specialObj) bool
 	TouchingColor(color Color) bool
-	Turn(val interface{})
-	TurnTo(obj interface{})
+	Turn__0(degree float64)
+	Turn__1(dir specialDir)
+	Turn__2(ti *TurningInfo)
+	TurnTo__0(sprite Sprite)
+	TurnTo__1(sprite SpriteName)
+	TurnTo__2(obj specialObj)
+	TurnTo__3(degree float64)
+	TurnTo__4(dir specialDir)
 	Visible() bool
 	Xpos() float64
 	Ypos() float64
 }
 
+type SpriteName = string
+
+type SpriteCostumeName = string
+
+type SpriteAnimationName = string
+
 type SpriteImpl struct {
 	baseObj
 	eventSinks
@@ -211,10 +239,10 @@ type SpriteImpl struct {
 
 	sayObj           *sayOrThinker
 	quoteObj         *quoter
-	animations       map[string]*aniConfig
+	animations       map[SpriteAnimationName]*aniConfig
 	greffUniforms    map[string]interface{} // graphic effects
 	animBindings     map[string]string
-	defaultAnimation string
+	defaultAnimation SpriteAnimationName
 
 	penColor color.RGBA
 	penShade float64
@@ -545,17 +573,17 @@ func (p *SpriteImpl) OnTouchStart__1(onTouchStart func()) {
 	})
 }
 
-func (p *SpriteImpl) OnTouchStart__2(name string, onTouchStart func(Sprite)) {
-	p.OnTouchStart__0(func(sprite Sprite) {
-		impl := spriteOf(sprite)
-		if impl != nil && impl.name == name {
-			onTouchStart(sprite)
+func (p *SpriteImpl) OnTouchStart__2(sprite SpriteName, onTouchStart func(Sprite)) {
+	p.OnTouchStart__0(func(s Sprite) {
+		impl := spriteOf(s)
+		if impl != nil && impl.name == sprite {
+			onTouchStart(s)
 		}
 	})
 }
 
-func (p *SpriteImpl) OnTouchStart__3(name string, onTouchStart func()) {
-	p.OnTouchStart__2(name, func(Sprite) {
+func (p *SpriteImpl) OnTouchStart__3(sprite SpriteName, onTouchStart func()) {
+	p.OnTouchStart__2(sprite, func(Sprite) {
 		onTouchStart()
 	})
 }
@@ -691,7 +719,7 @@ func (p *SpriteImpl) IsCloned() bool {
 
 // -----------------------------------------------------------------------------
 
-func (p *SpriteImpl) CostumeName() string {
+func (p *SpriteImpl) CostumeName() SpriteCostumeName {
 	return p.getCostumeName()
 }
 
@@ -699,7 +727,13 @@ func (p *SpriteImpl) CostumeIndex() int {
 	return p.getCostumeIndex()
 }
 
-func (p *SpriteImpl) SetCostume(costume interface{}) {
+// SetCostume func:
+//
+//	SetCostume(costume) or
+//	SetCostume(index) or
+//	SetCostume(spx.Next) or
+//	SetCostume(spx.Prev)
+func (p *SpriteImpl) setCostume(costume interface{}) {
 	if debugInstr {
 		log.Println("SetCostume", p.name, costume)
 	}
@@ -707,6 +741,22 @@ func (p *SpriteImpl) SetCostume(costume interface{}) {
 	p.defaultCostumeIndex = p.costumeIndex_
 }
 
+func (p *SpriteImpl) SetCostume__0(costume SpriteCostumeName) {
+	p.setCostume(costume)
+}
+
+func (p *SpriteImpl) SetCostume__1(index int) {
+	p.setCostume(index)
+}
+
+func (p *SpriteImpl) SetCostume__2(index float64) {
+	p.setCostume(index)
+}
+
+func (p *SpriteImpl) SetCostume__3(action switchAction) {
+	p.setCostume(action)
+}
+
 func (p *SpriteImpl) NextCostume() {
 	if debugInstr {
 		log.Println("NextCostume", p.name)
@@ -739,7 +789,7 @@ func (p *SpriteImpl) getFromAnToForAniFrames(from interface{}, to interface{}) (
 	fromval := 0.0
 	toval := 0.0
 	switch v := from.(type) {
-	case string:
+	case SpriteCostumeName:
 		fromval = float64(p.findCostume(v))
 		if fromval < 0 {
 			log.Panicf("findCostume %s failed", v)
@@ -749,7 +799,7 @@ func (p *SpriteImpl) getFromAnToForAniFrames(from interface{}, to interface{}) (
 	}
 
 	switch v := to.(type) {
-	case string:
+	case SpriteCostumeName:
 		toval = float64(p.findCostume(v))
 		if toval < 0 {
 			log.Panicf("findCostume %s failed", v)
@@ -771,10 +821,10 @@ func (p *SpriteImpl) getStateAnimName(stateName string) string {
 func lerp(a float64, b float64, progress float64) float64 {
 	return a + (b-a)*progress
 }
-func (p *SpriteImpl) goAnimate(name string, ani *aniConfig) {
+func (p *SpriteImpl) goAnimate(name SpriteAnimationName, ani *aniConfig) {
 	p.goAnimateInternal(name, ani, true)
 }
-func (p *SpriteImpl) goAnimateInternal(name string, ani *aniConfig, isBlocking bool) {
+func (p *SpriteImpl) goAnimateInternal(name SpriteAnimationName, ani *aniConfig, isBlocking bool) {
 	if p.lastAnim != nil {
 		p.isWaitingStopAnim = true
 		p.lastAnim.Stop()
@@ -947,7 +997,7 @@ func (p *SpriteImpl) goAnimateInternal(name string, ani *aniConfig, isBlocking b
 	}
 }
 
-func (p *SpriteImpl) Animate(name string) {
+func (p *SpriteImpl) Animate(name SpriteAnimationName) {
 	if debugInstr {
 		log.Println("==> Animation", name)
 	}
@@ -964,23 +1014,31 @@ func (p *SpriteImpl) Ask(msg interface{}) {
 	panic("todo")
 }
 
-func (p *SpriteImpl) Say(msg interface{}, secs ...float64) {
+func (p *SpriteImpl) Say__0(msg interface{}) {
+	p.Say__1(msg, 0)
+}
+
+func (p *SpriteImpl) Say__1(msg interface{}, secs float64) {
 	if debugInstr {
 		log.Println("Say", p.name, msg, secs)
 	}
 	p.sayOrThink(msg, styleSay)
-	if secs != nil {
-		p.waitStopSay(secs[0])
+	if secs > 0 {
+		p.waitStopSay(secs)
 	}
 }
 
-func (p *SpriteImpl) Think(msg interface{}, secs ...float64) {
+func (p *SpriteImpl) Think__0(msg interface{}) {
+	p.Think__1(msg, 0)
+}
+
+func (p *SpriteImpl) Think__1(msg interface{}, secs float64) {
 	if debugInstr {
 		log.Println("Think", p.name, msg, secs)
 	}
 	p.sayOrThink(msg, styleThink)
-	if secs != nil {
-		p.waitStopSay(secs[0])
+	if secs > 0 {
+		p.waitStopSay(secs)
 	}
 }
 
@@ -993,16 +1051,20 @@ func (p *SpriteImpl) Quote__0(message string) {
 }
 
 func (p *SpriteImpl) Quote__1(message string, secs float64) {
-	p.Quote__2(message, "", secs)
+	p.Quote__3(message, "", secs)
 }
 
-func (p *SpriteImpl) Quote__2(message, description string, secs ...float64) {
+func (p *SpriteImpl) Quote__2(message, description string) {
+	p.Quote__3(message, description, 0)
+}
+
+func (p *SpriteImpl) Quote__3(message, description string, secs float64) {
 	if debugInstr {
 		log.Println("Quote", p.name, message, description, secs)
 	}
 	p.quote_(message, description)
-	if secs != nil {
-		p.waitStopQuote(secs[0])
+	if secs > 0 {
+		p.waitStopQuote(secs)
 	}
 }
 
@@ -1015,10 +1077,9 @@ func (p *SpriteImpl) getXY() (x, y float64) {
 // DistanceTo func:
 //
 //	DistanceTo(sprite)
-//	DistanceTo(spriteName)
 //	DistanceTo(spx.Mouse)
 //	DistanceTo(spx.Random)
-func (p *SpriteImpl) DistanceTo(obj interface{}) float64 {
+func (p *SpriteImpl) distanceTo(obj interface{}) float64 {
 	x, y := p.x, p.y
 	x2, y2 := p.g.objectPos(obj)
 	x -= x2
@@ -1026,6 +1087,22 @@ func (p *SpriteImpl) DistanceTo(obj interface{}) float64 {
 	return math.Sqrt(x*x + y*y)
 }
 
+func (p *SpriteImpl) DistanceTo__0(sprite Sprite) float64 {
+	return p.distanceTo(sprite)
+}
+
+func (p *SpriteImpl) DistanceTo__1(sprite SpriteName) float64 {
+	return p.distanceTo(sprite)
+}
+
+func (p *SpriteImpl) DistanceTo__2(obj specialObj) float64 {
+	return p.distanceTo(obj)
+}
+
+func (p *SpriteImpl) DistanceTo__3(pos Pos) float64 {
+	return p.distanceTo(pos)
+}
+
 func (p *SpriteImpl) doMoveTo(x, y float64) {
 	p.doMoveToForAnim(x, y, nil)
 }
@@ -1068,18 +1145,18 @@ func (p *SpriteImpl) Step__1(step int) {
 	p.Step__0(float64(step))
 }
 
-func (p *SpriteImpl) Step__2(step float64, animname string) {
+func (p *SpriteImpl) Step__2(step float64, animation SpriteAnimationName) {
 	if debugInstr {
 		log.Println("Step", p.name, step)
 	}
-	if ani, ok := p.animations[animname]; ok {
+	if ani, ok := p.animations[animation]; ok {
 		anicopy := *ani
 		anicopy.From = 0
 		anicopy.To = step
 		anicopy.AniType = aniTypeMove
 		anicopy.Duration = math.Abs(step) * ani.StepDuration
 
-		p.goAnimate(animname, &anicopy)
+		p.goAnimate(animation, &anicopy)
 		return
 	}
 	p.goMoveForward(step)
@@ -1107,10 +1184,9 @@ func (p *SpriteImpl) playDefaultAnim() {
 // Goto func:
 //
 //	Goto(sprite)
-//	Goto(spriteName)
 //	Goto(spx.Mouse)
 //	Goto(spx.Random)
-func (p *SpriteImpl) Goto(obj interface{}) {
+func (p *SpriteImpl) goGoto(obj interface{}) {
 	if debugInstr {
 		log.Println("Goto", p.name, obj)
 	}
@@ -1118,6 +1194,18 @@ func (p *SpriteImpl) Goto(obj interface{}) {
 	p.SetXYpos(x, y)
 }
 
+func (p *SpriteImpl) Goto__0(sprite Sprite) {
+	p.goGoto(sprite)
+}
+
+func (p *SpriteImpl) Goto__1(sprite SpriteName) {
+	p.goGoto(sprite)
+}
+
+func (p *SpriteImpl) Goto__2(obj specialObj) {
+	p.goGoto(obj)
+}
+
 func (p *SpriteImpl) Glide__0(x, y float64, secs float64) {
 	if debugInstr {
 		log.Println("Glide", p.name, x, y, secs)
@@ -1134,7 +1222,7 @@ func (p *SpriteImpl) Glide__0(x, y float64, secs float64) {
 	p.goAnimate(animName, ani)
 }
 
-func (p *SpriteImpl) Glide__1(obj interface{}, secs float64) {
+func (p *SpriteImpl) goGlide(obj interface{}, secs float64) {
 	if debugInstr {
 		log.Println("Glide", obj, secs)
 	}
@@ -1142,6 +1230,22 @@ func (p *SpriteImpl) Glide__1(obj interface{}, secs float64) {
 	p.Glide__0(x, y, secs)
 }
 
+func (p *SpriteImpl) Glide__1(sprite Sprite, secs float64) {
+	p.goGlide(sprite, secs)
+}
+
+func (p *SpriteImpl) Glide__2(sprite SpriteName, secs float64) {
+	p.goGlide(sprite, secs)
+}
+
+func (p *SpriteImpl) Glide__3(obj specialObj, secs float64) {
+	p.goGlide(obj, secs)
+}
+
+func (p *SpriteImpl) Glide__4(pos Pos, secs float64) {
+	p.goGlide(pos, secs)
+}
+
 func (p *SpriteImpl) SetXYpos(x, y float64) {
 	p.doMoveTo(x, y)
 }
@@ -1211,7 +1315,7 @@ func (p *SpriteImpl) Heading() float64 {
 //	Turn(spx.Left)
 //	Turn(spx.Right)
 //	Turn(ti *spx.TurningInfo)
-func (p *SpriteImpl) Turn(val interface{}) {
+func (p *SpriteImpl) turn(val interface{}) {
 	var delta float64
 	switch v := val.(type) {
 	//case specialDir:
@@ -1240,17 +1344,28 @@ func (p *SpriteImpl) Turn(val interface{}) {
 	}
 }
 
+func (p *SpriteImpl) Turn__0(degree float64) {
+	p.turn(degree)
+}
+
+func (p *SpriteImpl) Turn__1(dir specialDir) {
+	p.turn(dir)
+}
+
+func (p *SpriteImpl) Turn__2(ti *TurningInfo) {
+	p.turn(ti)
+}
+
 // TurnTo func:
 //
 //	TurnTo(sprite)
-//	TurnTo(spriteName)
 //	TurnTo(spx.Mouse)
 //	TurnTo(degree)
 //	TurnTo(spx.Left)
 //	TurnTo(spx.Right)
 //	TurnTo(spx.Up)
 //	TurnTo(spx.Down)
-func (p *SpriteImpl) TurnTo(obj interface{}) {
+func (p *SpriteImpl) turnTo(obj interface{}) {
 	var angle float64
 	switch v := obj.(type) {
 	//case specialDir:
@@ -1290,6 +1405,26 @@ func (p *SpriteImpl) TurnTo(obj interface{}) {
 	}
 }
 
+func (p *SpriteImpl) TurnTo__0(sprite Sprite) {
+	p.turnTo(sprite)
+}
+
+func (p *SpriteImpl) TurnTo__1(sprite SpriteName) {
+	p.turnTo(sprite)
+}
+
+func (p *SpriteImpl) TurnTo__2(obj specialObj) {
+	p.turnTo(obj)
+}
+
+func (p *SpriteImpl) TurnTo__3(degree float64) {
+	p.turnTo(degree)
+}
+
+func (p *SpriteImpl) TurnTo__4(dir specialDir) {
+	p.turnTo(dir)
+}
+
 func (p *SpriteImpl) SetHeading(dir float64) {
 	p.setDirection(dir, false)
 }
@@ -1397,7 +1532,6 @@ func (p *SpriteImpl) TouchingColor(color Color) bool {
 
 // Touching func:
 //
-//	Touching(spriteName)
 //	Touching(sprite)
 //	Touching(spx.Mouse)
 //	Touching(spx.Edge)
@@ -1405,12 +1539,12 @@ func (p *SpriteImpl) TouchingColor(color Color) bool {
 //	Touching(spx.EdgeTop)
 //	Touching(spx.EdgeRight)
 //	Touching(spx.EdgeBottom)
-func (p *SpriteImpl) Touching(obj interface{}) bool {
+func (p *SpriteImpl) touching(obj interface{}) bool {
 	if !p.isVisible || p.isDying {
 		return false
 	}
 	switch v := obj.(type) {
-	case string:
+	case SpriteName:
 		if o := p.g.touchingSpriteBy(p, v); o != nil {
 			return true
 		}
@@ -1428,6 +1562,18 @@ func (p *SpriteImpl) Touching(obj interface{}) bool {
 	panic("Touching: unexpected input")
 }
 
+func (p *SpriteImpl) Touching__0(sprite SpriteName) bool {
+	return p.touching(sprite)
+}
+
+func (p *SpriteImpl) Touching__1(sprite Sprite) bool {
+	return p.touching(sprite)
+}
+
+func (p *SpriteImpl) Touching__2(obj specialObj) bool {
+	return p.touching(obj)
+}
+
 func touchingSprite(dst, src *SpriteImpl) bool {
 	if !src.isVisible || src.isDying {
 		return false
diff --git a/widget.go b/widget.go
index 491655a0..500a4737 100644
--- a/widget.go
+++ b/widget.go
@@ -1,7 +1,7 @@
 package spx
 
 type Widget interface {
-	GetName() string
+	GetName() WidgetName
 	Visible() bool
 	Show()
 	Hide()
@@ -19,3 +19,5 @@ type Widget interface {
 	SetSize(size float64)
 	ChangeSize(delta float64)
 }
+
+type WidgetName = string