diff --git a/dev-assets/doodads/azulian/Makefile b/dev-assets/doodads/azulian/Makefile
index 20e7aa5..05dae89 100644
--- a/dev-assets/doodads/azulian/Makefile
+++ b/dev-assets/doodads/azulian/Makefile
@@ -4,11 +4,13 @@ ALL: build
 build:
 	doodad convert -t "Blue Azulian" blu-front.png blu-back.png \
 		blu-wr{1,2,3,4}.png blu-wl{1,2,3,4}.png azu-blu.doodad
+	doodad edit-doodad --tag "color=blue" azu-blu.doodad
 	doodad install-script azulian.js azu-blu.doodad
 
 	doodad convert -t "Red Azulian" red-front.png red-back.png \
 		red-wr{1,2,3,4}.png red-wl{1,2,3,4}.png azu-red.doodad
-	doodad install-script azulian-red.js azu-red.doodad
+	doodad edit-doodad --tag "color=red" azu-red.doodad
+	doodad install-script azulian.js azu-red.doodad
 
 	# Tag the category for these doodads
 	for i in *.doodad; do\
diff --git a/dev-assets/doodads/azulian/azulian-red.js b/dev-assets/doodads/azulian/azulian-red.js
index f42d92d..aeb5f91 100644
--- a/dev-assets/doodads/azulian/azulian-red.js
+++ b/dev-assets/doodads/azulian/azulian-red.js
@@ -1,3 +1,6 @@
+// Azulian (Red)
+// DEPRECATED: they both share azulian.js now.
+
 function main() {
 	var playerSpeed = 4;
 	var gravity = 4;
diff --git a/dev-assets/doodads/azulian/azulian.js b/dev-assets/doodads/azulian/azulian.js
index 3aa7637..54db87e 100644
--- a/dev-assets/doodads/azulian/azulian.js
+++ b/dev-assets/doodads/azulian/azulian.js
@@ -1,38 +1,74 @@
-function main() {
-	var playerSpeed = 12;
-	var gravity = 4;
-	var Vx = Vy = 0;
+// Azulian (Red and Blue)
+var playerSpeed = 12,
+	animating = false,
+	direction = "right";
 
-	var animating = false;
-	var animStart = animEnd = 0;
-	var animFrame = animStart;
+function setupAnimations(color) {
+	var left = color === 'blue' ? 'blu-wl' : 'red-wl',
+		right = color === 'blue' ? 'blu-wr' : 'red-wr',
+		leftFrames = [left + '1', left + '2', left + '3', left + '4'],
+		rightFrames = [right + '1', right + '2', right + '3', right + '4'];
+
+	Self.AddAnimation("walk-left", 100, leftFrames);
+	Self.AddAnimation("walk-right", 100, rightFrames);
+}
+
+function main() {
+	var color = Self.GetTag("color");
+	playerSpeed = color === 'blue' ? 2 : 4;
 
 	Self.SetMobile(true);
 	Self.SetGravity(true);
 	Self.SetInventory(true);
-	Self.SetHitbox(7, 4, 17, 28);
-	Self.AddAnimation("walk-left", 100, ["blu-wl1", "blu-wl2", "blu-wl3", "blu-wl4"]);
-	Self.AddAnimation("walk-right", 100, ["blu-wr1", "blu-wr2", "blu-wr3", "blu-wr4"]);
+	Self.SetHitbox(0, 0, 24, 32);
+	setupAnimations(color);
 
+	if (Self.IsPlayer()) {
+		return playerControls();
+	}
+
+	// A.I. pattern: walks back and forth, turning around
+	// when it meets resistance.
+
+	// Sample our X position every few frames and detect if we've hit a solid wall.
+	var sampleTick = 0;
+	var sampleRate = 5;
+	var lastSampledX = 0;
+
+	setInterval(function () {
+		if (sampleTick % sampleRate === 0) {
+			var curX = Self.Position().X;
+			var delta = Math.abs(curX - lastSampledX);
+			if (delta < 5) {
+				direction = direction === "right" ? "left" : "right";
+			}
+			lastSampledX = curX;
+		}
+		sampleTick++;
+
+		var Vx = parseFloat(playerSpeed * (direction === "left" ? -1 : 1));
+		Self.SetVelocity(Vector(Vx, 0.0));
+
+		if (!Self.IsAnimating()) {
+			Self.PlayAnimation("walk-" + direction, null);
+		}
+	}, 100);
+}
+
+function playerControls() {
+	// Note: player speed is controlled by the engine.
 	Events.OnKeypress(function (ev) {
-		Vx = 0;
-		Vy = 0;
-
 		if (ev.Right) {
 			if (!Self.IsAnimating()) {
 				Self.PlayAnimation("walk-right", null);
 			}
-			Vx = playerSpeed;
 		} else if (ev.Left) {
 			if (!Self.IsAnimating()) {
 				Self.PlayAnimation("walk-left", null);
 			}
-			Vx = -playerSpeed;
 		} else {
 			Self.StopAnimation();
 			animating = false;
 		}
-
-		// Self.SetVelocity(Point(Vx, Vy));
 	})
 }
diff --git a/dev-assets/doodads/build.sh b/dev-assets/doodads/build.sh
index 9c99564..d115872 100755
--- a/dev-assets/doodads/build.sh
+++ b/dev-assets/doodads/build.sh
@@ -91,5 +91,5 @@ objects
 onoff
 warpdoor
 doodad edit-doodad -quiet -lock -author "Noah" ../../assets/doodads/*.doodad
-doodad edit-doodad -hide ../../assets/doodads/azu-blu.doodad
+doodad edit-doodad ../../assets/doodads/azu-blu.doodad
 doodad edit-doodad -hide ../../assets/doodads/boy.doodad
diff --git a/dev-assets/doodads/objects/Makefile b/dev-assets/doodads/objects/Makefile
index c56b8ed..86e33ce 100644
--- a/dev-assets/doodads/objects/Makefile
+++ b/dev-assets/doodads/objects/Makefile
@@ -4,6 +4,7 @@ ALL: build
 build:
 	# Start Flag
 	doodad convert -t "Start Flag" start-flag.png start-flag.doodad
+	doodad install-script start-flag.js start-flag.doodad
 
 	# Exit Flag
 	doodad convert -t "Exit Flag" exit-flag.png exit-flag.doodad
diff --git a/dev-assets/doodads/objects/start-flag.js b/dev-assets/doodads/objects/start-flag.js
new file mode 100644
index 0000000..dc84a77
--- /dev/null
+++ b/dev-assets/doodads/objects/start-flag.js
@@ -0,0 +1,11 @@
+// Start Flag.
+function main() {
+    Self.SetHitbox(22 + 16, 16, 75 - 16, 86);
+
+    // Linking a doodad to the Start Flag sets the
+    // player character. Destroy the original doodads.
+    var links = Self.GetLinks();
+    for (var i = 0; i < links.length; i++) {
+        links[i].Destroy();
+    }
+}
diff --git a/pkg/balance/numbers.go b/pkg/balance/numbers.go
index d269a78..154ad5a 100644
--- a/pkg/balance/numbers.go
+++ b/pkg/balance/numbers.go
@@ -13,7 +13,7 @@ var (
 
 	// Window scrolling behavior in Play Mode.
 	ScrollboxOffset = render.Point{ // from center of screen
-		X: 40,
+		X: 60,
 		Y: 100,
 	}
 
diff --git a/pkg/doodads/drawing.go b/pkg/doodads/drawing.go
index 2ccc1b5..f57a282 100644
--- a/pkg/doodads/drawing.go
+++ b/pkg/doodads/drawing.go
@@ -22,7 +22,7 @@ type Drawing struct {
 // an empty ID string, it will make a random UUIDv4 ID.
 func NewDrawing(id string, doodad *Doodad) *Drawing {
 	if id == "" {
-		id = uuid.Must(uuid.NewRandom()).String()
+		id = uuid.Must(uuid.NewUUID()).String()
 	}
 	return &Drawing{
 		id:     id,
diff --git a/pkg/editor_ui.go b/pkg/editor_ui.go
index 1609089..91d5509 100644
--- a/pkg/editor_ui.go
+++ b/pkg/editor_ui.go
@@ -378,6 +378,7 @@ func (u *EditorUI) SetupCanvas(d *Doodle) *uix.Canvas {
 			for _, actor := range actors {
 				u.Scene.Level.Actors.Remove(actor)
 			}
+			u.Scene.Level.PruneLinks()
 			drawing.InstallActors(u.Scene.Level.Actors)
 		}
 	}
@@ -395,8 +396,15 @@ func (u *EditorUI) SetupCanvas(d *Doodle) *uix.Canvas {
 		// The actors are a uix.Actor which houses a level.Actor which we
 		// want to update to map each other's IDs.
 		idA, idB := a.Actor.ID(), b.Actor.ID()
-		a.Actor.AddLink(idB)
-		b.Actor.AddLink(idA)
+
+		// Are they already linked?
+		if a.Actor.IsLinked(idB) || b.Actor.IsLinked(idA) {
+			a.Actor.Unlink(idB)
+			b.Actor.Unlink(idA)
+		} else {
+			a.Actor.AddLink(idB)
+			b.Actor.AddLink(idA)
+		}
 
 		// Reset the Link tool.
 		d.Flash("Linked '%s' and '%s' together", a.Doodad().Title, b.Doodad().Title)
diff --git a/pkg/level/actors.go b/pkg/level/actors.go
index 3d1ba1d..6fd7567 100644
--- a/pkg/level/actors.go
+++ b/pkg/level/actors.go
@@ -19,7 +19,7 @@ func (m ActorMap) Inflate() {
 // given a random UUIDv4 ID.
 func (m ActorMap) Add(a *Actor) {
 	if a.id == "" {
-		a.id = uuid.Must(uuid.NewRandom()).String()
+		a.id = uuid.Must(uuid.NewUUID()).String()
 	}
 	m[a.id] = a
 }
@@ -57,3 +57,25 @@ func (a *Actor) AddLink(id string) {
 	}
 	a.Links = append(a.Links, id)
 }
+
+// Unlink removes the linked actor's ID.
+func (a *Actor) Unlink(id string) {
+	var newLinks []string
+	for _, exist := range a.Links {
+		if exist == id {
+			continue
+		}
+		newLinks = append(newLinks, exist)
+	}
+	a.Links = newLinks
+}
+
+// IsLinked checks if the actor is linked to the other actor's ID.
+func (a *Actor) IsLinked(id string) bool {
+	for _, exist := range a.Links {
+		if exist == id {
+			return true
+		}
+	}
+	return false
+}
diff --git a/pkg/level/chunk.go b/pkg/level/chunk.go
index f348d7e..e506b85 100644
--- a/pkg/level/chunk.go
+++ b/pkg/level/chunk.go
@@ -134,7 +134,7 @@ func (c *Chunk) generateTexture(mask render.Color) (render.Texturer, error) {
 	// Generate a unique name for this chunk cache.
 	var name string
 	if c.uuid == uuid.Nil {
-		c.uuid = uuid.Must(uuid.NewRandom())
+		c.uuid = uuid.Must(uuid.NewUUID())
 	}
 	name = c.uuid.String()
 
diff --git a/pkg/play_scene.go b/pkg/play_scene.go
index 9df0f04..977b6dd 100644
--- a/pkg/play_scene.go
+++ b/pkg/play_scene.go
@@ -251,40 +251,51 @@ func (s *PlayScene) setupAsync(d *Doodle) error {
 
 // setupPlayer creates and configures the Player Character in the level.
 func (s *PlayScene) setupPlayer() {
-	// Load in the player character.
-	player, err := doodads.LoadFile(balance.PlayerCharacterDoodad)
-	if err != nil {
-		log.Error("PlayScene.Setup: failed to load player doodad: %s", err)
-		player = doodads.NewDummy(32)
-	}
-
 	// Find the spawn point of the player. Search the level for the
 	// "start-flag.doodad"
 	var (
+		playerCharacterFilename = balance.PlayerCharacterDoodad
+
 		spawn     render.Point
+		flag      *level.Actor
+		flagSize  = render.NewRect(86, 86) // TODO: start-flag.doodad is 86x86 px
 		flagCount int
 	)
 	for actorID, actor := range s.Level.Actors {
 		if actor.Filename == "start-flag.doodad" {
-			if flagCount > 1 {
+			// Support alternative player characters: if the Start Flag is linked
+			// to another actor, that actor becomes the player character.
+			for _, linkID := range actor.Links {
+				if linkedActor, ok := s.Level.Actors[linkID]; ok {
+					playerCharacterFilename = linkedActor.Filename
+					log.Info("Playing as: %s", playerCharacterFilename)
+				}
 				break
 			}
 
 			// TODO: start-flag.doodad is 86x86 pixels but we can't tell that
 			// from right here.
-			size := render.NewRect(86, 86)
 			log.Info("Found start-flag.doodad at %s (ID %s)", actor.Point, actorID)
-			spawn = render.NewPoint(
-				// X: centered inside the flag.
-				actor.Point.X+(size.W/2)-(player.Layers[0].Chunker.Size/2),
-
-				// Y: the bottom of the flag, 4 pixels from the floor.
-				actor.Point.Y+size.H-4-(player.Layers[0].Chunker.Size),
-			)
-			flagCount++
+			flag = actor
+			break
 		}
 	}
 
+	// Load in the player character.
+	player, err := doodads.LoadFile(playerCharacterFilename)
+	if err != nil {
+		log.Error("PlayScene.Setup: failed to load player doodad: %s", err)
+		player = doodads.NewDummy(32)
+	}
+
+	spawn = render.NewPoint(
+		// X: centered inside the flag.
+		flag.Point.X+(flagSize.W/2)-(player.Layers[0].Chunker.Size/2),
+
+		// Y: the bottom of the flag, 4 pixels from the floor.
+		flag.Point.Y+flagSize.H-4-(player.Layers[0].Chunker.Size),
+	)
+
 	// Surface warnings around the spawn flag.
 	if flagCount == 0 {
 		s.d.Flash("Warning: this level contained no Start Flag.")
diff --git a/pkg/uix/actor.go b/pkg/uix/actor.go
index 970080a..2b0643a 100644
--- a/pkg/uix/actor.go
+++ b/pkg/uix/actor.go
@@ -63,7 +63,7 @@ type Actor struct {
 // If the id is blank, a new UUIDv4 is generated.
 func NewActor(id string, levelActor *level.Actor, doodad *doodads.Doodad) *Actor {
 	if id == "" {
-		id = uuid.Must(uuid.NewRandom()).String()
+		id = uuid.Must(uuid.NewUUID()).String()
 	}
 
 	size := doodad.Layers[0].Chunker.Size