diff --git a/Changes.md b/Changes.md
index 7dd24a2..59b31c4 100644
--- a/Changes.md
+++ b/Changes.md
@@ -1,5 +1,26 @@
 # Changes
 
+## v0.4.0-alpha
+
+This update brings improvements to the editor; you can now fully draw all the
+graphics for a custom doodad using the in-app tools!
+
+A key difference between a Level and a Doodad is that doodads have **Layers**
+where they keep multiple frames of animation or state. The editor tool now
+supports working with these extra layers.
+
+Other new features:
+
+* The **Guidebook** has been updated with tons of good info and screenshots of
+  the game's features. Press `F1` in-game to open the guidebook, or check it
+  online at https://www.sketchymaze.com/guidebook/
+* **Layer Selection Window for Doodads:** when you're editing a Doodad drawing,
+  a "Lyr." button is added to the toolbar to access the Layers window.
+* **Global UI popup modals:** when you're about to close a level with unsaved
+  changes, you get an Ok/Cancel prompt confirming if you want to do that.
+  Hitting the Escape key will ask you before just exiting the program. Alert
+  boxes are supported too, and an `alert` command added to the developer console.
+
 ## v0.3.0-alpha
 
 This update introduces the player character to the game. He doesn't have a name;
diff --git a/pkg/commands.go b/pkg/commands.go
index efaf3cb..6209418 100644
--- a/pkg/commands.go
+++ b/pkg/commands.go
@@ -3,10 +3,14 @@ package doodle
 import (
 	"errors"
 	"fmt"
+	"os"
+	"path/filepath"
 	"strconv"
 
 	"git.kirsle.net/apps/doodle/pkg/balance"
+	"git.kirsle.net/apps/doodle/pkg/bindata"
 	"git.kirsle.net/apps/doodle/pkg/enum"
+	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/modal"
 	"github.com/robertkrimen/otto"
 )
@@ -69,6 +73,9 @@ func (c Command) Run(d *Doodle) error {
 		d.shell.Text = "$ "
 	case "boolProp":
 		return c.BoolProp(d)
+	case "extract-bindata":
+		// Undocumented command to extract the binary of its assets.
+		return c.ExtractBindata(d, c.ArgsLiteral)
 	default:
 		return c.Default()
 	}
@@ -88,6 +95,47 @@ func (c Command) Close(d *Doodle) error {
 	return nil
 }
 
+// ExtractBindata dumps the app's embedded bindata to the filesystem.
+func (c Command) ExtractBindata(d *Doodle, path string) error {
+	if len(path) == 0 || path[0] != '/' {
+		d.Flash("Required: an absolute path to a directory to extract to.")
+		return nil
+	}
+
+	err := os.MkdirAll(path, 0755)
+	if err != nil {
+		d.Flash("MkdirAll: %s", err)
+		return err
+	}
+
+	for _, filename := range bindata.AssetNames() {
+		outfile := filepath.Join(path, filename)
+		log.Info("Extracting bindata: %s    to: %s", filename, outfile)
+
+		data, err := bindata.Asset(filename)
+		if err != nil {
+			d.Flash("error on file %s: %s", filename, err)
+			continue
+		}
+
+		// Fill out the directory path.
+		if _, err := os.Stat(filepath.Dir(outfile)); os.IsNotExist(err) {
+			os.MkdirAll(filepath.Dir(outfile), 0755)
+		}
+
+		fh, err := os.Create(outfile)
+		if err != nil {
+			d.Flash("error writing file %s: %s", outfile, err)
+			continue
+		}
+		fh.Write(data)
+		fh.Close()
+	}
+
+	d.Flash("Bindata extracted to %s", path)
+	return nil
+}
+
 // Help prints the help info.
 func (c Command) Help(d *Doodle) error {
 	if len(c.Args) == 0 {
diff --git a/pkg/doodle.go b/pkg/doodle.go
index 17d7ae1..83e0125 100644
--- a/pkg/doodle.go
+++ b/pkg/doodle.go
@@ -146,8 +146,8 @@ func (d *Doodle) Run() error {
 			}
 
 			if keybind.Help(ev) {
-				// TODO: launch the guidebook.
-				native.OpenURL(balance.GuidebookPath)
+				// Launch the local guidebook
+				native.OpenLocalURL(balance.GuidebookPath)
 			} else if keybind.DebugOverlay(ev) {
 				DebugOverlay = !DebugOverlay
 			} else if keybind.DebugCollision(ev) {
diff --git a/pkg/editor_ui.go b/pkg/editor_ui.go
index d02cc3d..1640cd5 100644
--- a/pkg/editor_ui.go
+++ b/pkg/editor_ui.go
@@ -654,8 +654,7 @@ func (u *EditorUI) SetupMenuBar(d *Doodle) *ui.MenuBar {
 	// Help menu
 	helpMenu := menu.AddMenu("Help")
 	helpMenu.AddItemAccel("User Manual", "F1", func() {
-		// TODO: launch the guidebook.
-		native.OpenURL(balance.GuidebookPath)
+		native.OpenLocalURL(balance.GuidebookPath)
 	})
 	helpMenu.AddItem("About", func() {
 		if u.aboutWindow == nil {
diff --git a/pkg/native/browser.go b/pkg/native/browser.go
index 4ed4339..3503538 100644
--- a/pkg/native/browser.go
+++ b/pkg/native/browser.go
@@ -3,7 +3,9 @@
 package native
 
 import (
+	"fmt"
 	"os/exec"
+	"path/filepath"
 	"runtime"
 
 	"git.kirsle.net/apps/doodle/pkg/log"
@@ -26,6 +28,16 @@ func OpenURL(url string) {
 	}
 }
 
+// OpenLocalURL opens a web browser to a local HTML path.
+// It converts a relative path like "guidebook/index.html" to its absolute
+// filesystem location.
+func OpenLocalURL(path string) {
+	abs, _ := filepath.Abs(path)
+	url := fmt.Sprintf("file:///%s", abs)
+	fmt.Printf("Open Local URL: %s\n", url)
+	OpenURL(url)
+}
+
 func windowsOpenURL(url string) {
 	_, err := exec.Command("start", url).Output()
 	if err != nil {