diff --git a/pkg/balance/theme.go b/pkg/balance/theme.go
index 53d19f7..f061b5f 100644
--- a/pkg/balance/theme.go
+++ b/pkg/balance/theme.go
@@ -77,6 +77,13 @@ var (
 		Color:        render.Black,
 	}
 
+	// Small font
+	SmallFont = render.Text{
+		Size:    10,
+		Padding: 4,
+		Color:   render.Black,
+	}
+
 	// Color for draggable doodad.
 	DragColor = render.MustHexColor("#0099FF")
 
@@ -101,6 +108,7 @@ var (
 
 	// Button styles, customized in init().
 	ButtonPrimary = style.DefaultButton
+	ButtonDanger  = style.DefaultButton
 )
 
 func init() {
@@ -109,4 +117,9 @@ func init() {
 	ButtonPrimary.Foreground = render.RGBA(255, 255, 254, 255)
 	ButtonPrimary.HoverBackground = render.RGBA(0, 153, 255, 255)
 	ButtonPrimary.HoverForeground = ButtonPrimary.Foreground
+
+	ButtonDanger.Background = render.RGBA(153, 30, 30, 255)
+	ButtonDanger.Foreground = render.RGBA(255, 255, 254, 255)
+	ButtonDanger.HoverBackground = render.RGBA(255, 30, 30, 255)
+	ButtonDanger.HoverForeground = ButtonPrimary.Foreground
 }
diff --git a/pkg/editor_ui.go b/pkg/editor_ui.go
index e3af690..68ccf5d 100644
--- a/pkg/editor_ui.go
+++ b/pkg/editor_ui.go
@@ -50,27 +50,18 @@ type EditorUI struct {
 	paletteEditor       *ui.Window
 	layersWindow        *ui.Window
 	publishWindow       *ui.Window
+	filesystemWindow    *ui.Window
 
 	// Palette window.
 	Palette    *ui.Window
 	PaletteTab *ui.Frame
 	DoodadTab  *ui.Frame
 
-	// Doodad Palette window variables.
-	doodadSkip       int
-	doodadRows       []*ui.Frame
-	doodadPager      *ui.Frame
-	doodadButtonSize int
-	doodadScroller   *ui.Frame
-
 	// ToolBar window.
 	activeTool string
 
 	// Draggable Doodad canvas.
 	DraggableActor *DraggableActor
-
-	// Palette variables.
-	paletteTab string // selected tab, Palette or Doodads
 }
 
 // NewEditorUI initializes the Editor UI.
@@ -568,6 +559,10 @@ func (u *EditorUI) SetupMenuBar(d *Doodle) *ui.MenuBar {
 			u.SetupPopups(u.d)
 			u.levelSettingsWindow.Show()
 		})
+		levelMenu.AddItem("Attached files", func() {
+			log.Info("Opening the FileSystem window")
+			u.OpenFileSystemWindow()
+		})
 		levelMenu.AddItemAccel("Playtest", "P", func() {
 			u.Scene.Playtest()
 		})
diff --git a/pkg/editor_ui_popups.go b/pkg/editor_ui_popups.go
index 4958e86..aad8889 100644
--- a/pkg/editor_ui_popups.go
+++ b/pkg/editor_ui_popups.go
@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"git.kirsle.net/apps/doodle/pkg/balance"
 	"git.kirsle.net/apps/doodle/pkg/doodads"
 	"git.kirsle.net/apps/doodle/pkg/level"
 	"git.kirsle.net/apps/doodle/pkg/level/publishing"
@@ -56,6 +57,14 @@ func (u *EditorUI) OpenPublishWindow() {
 	u.publishWindow.Show()
 }
 
+// OpenPublishWindow opens the FileSystem window.
+func (u *EditorUI) OpenFileSystemWindow() {
+	u.filesystemWindow.Hide()
+	u.filesystemWindow = nil
+	u.SetupPopups(u.d)
+	u.filesystemWindow.Show()
+}
+
 // SetupPopups preloads popup windows like the DoodadDropper.
 func (u *EditorUI) SetupPopups(d *Doodle) {
 	// Common window configure function.
@@ -147,6 +156,54 @@ func (u *EditorUI) SetupPopups(d *Doodle) {
 		configure(u.publishWindow)
 	}
 
+	// Level FileSystem Viewer.
+	if u.filesystemWindow == nil {
+		scene, _ := d.Scene.(*EditorScene)
+
+		u.filesystemWindow = windows.NewFileSystemWindow(windows.FileSystem{
+			Supervisor: u.Supervisor,
+			Engine:     d.Engine,
+			Level:      scene.Level,
+
+			OnDelete: func(filename string) bool {
+				// Check if it is an embedded doodad.
+				if strings.HasPrefix(filename, balance.EmbeddedDoodadsBasePath) {
+					// Check if we have the doodad installed locally.
+					if _, err := doodads.LoadFile(filepath.Base(filename)); err != nil {
+						modal.Alert(
+							"Cannot remove %s:\n\n"+
+								"This doodad is still in use by the level and does not\n"+
+								"exist on your local device, so can not be deleted.",
+							filepath.Base(filename),
+						).WithTitle("Cannot Remove Custom Doodad")
+						return false
+					}
+				}
+
+				// Can't delete the current wallpaper.
+				if filepath.Base(filename) == scene.Level.Wallpaper {
+					modal.Alert(
+						"This wallpaper is still in use as the level background, so can\n" +
+							"not be deleted. Change the wallpaper in the Page Settings window\n" +
+							"to one of the defaults and then you may remove this file from the level.",
+					).WithTitle("Cannot Remove Current Wallpaper")
+					return false
+				}
+
+				if ok := scene.Level.DeleteFile(filename); !ok {
+					modal.Alert("Failed to remove file from level data!")
+					return false
+				}
+
+				return true
+			},
+			OnCancel: func() {
+				u.filesystemWindow.Hide()
+			},
+		})
+		configure(u.filesystemWindow)
+	}
+
 	// Palette Editor.
 	if u.paletteEditor == nil {
 		scene, _ := d.Scene.(*EditorScene)
diff --git a/pkg/level/filesystem.go b/pkg/level/filesystem.go
index 13683c7..a79763f 100644
--- a/pkg/level/filesystem.go
+++ b/pkg/level/filesystem.go
@@ -54,7 +54,7 @@ func (l *Level) DeleteFile(filename string) bool {
 func (l *Level) ListFiles() []string {
 	var files []string
 
-	if l.Files == nil {
+	if l == nil || l.Files == nil {
 		return files
 	}
 
diff --git a/pkg/windows/filesystem_window.go b/pkg/windows/filesystem_window.go
new file mode 100644
index 0000000..580df2b
--- /dev/null
+++ b/pkg/windows/filesystem_window.go
@@ -0,0 +1,260 @@
+package windows
+
+import (
+	"fmt"
+	"math"
+
+	"git.kirsle.net/apps/doodle/pkg/balance"
+	"git.kirsle.net/apps/doodle/pkg/level"
+	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/go/render"
+	"git.kirsle.net/go/ui"
+)
+
+// FileSystem window shows the file attachments to the current level.
+type FileSystem struct {
+	// Settings passed in by doodle
+	Supervisor *ui.Supervisor
+	Engine     render.Engine
+	Level      *level.Level
+
+	OnDelete func(filename string) bool
+	OnCancel func()
+
+	// Private vars.
+	includeBuiltins bool // show built-in doodads in checkbox-list.
+}
+
+// NewFileSystemWindow initializes the window.
+func NewFileSystemWindow(cfg FileSystem) *ui.Window {
+	var (
+		windowColor      = render.RGBA(255, 255, 200, 255)
+		windowTitleColor = render.RGBA(255, 153, 0, 255)
+		windowWidth      = 380
+		windowHeight     = 360
+		page             = 1
+		perPage          = 6
+		pages            = 1
+		maxPageButtons   = 8
+
+		// columns and sizes to draw the doodad list
+		btnHeight = 14
+	)
+
+	window := ui.NewWindow("Attached Files")
+	window.SetButtons(ui.CloseButton)
+	window.ActiveTitleBackground = windowTitleColor // TODO: not working?
+	window.InactiveTitleBackground = windowTitleColor.Darken(60)
+	window.InactiveTitleForeground = render.Grey
+	window.Configure(ui.Config{
+		Width:      windowWidth,
+		Height:     windowHeight,
+		Background: windowColor,
+	})
+
+	/////////////
+	// Intro text
+
+	introFrame := ui.NewFrame("Intro Frame")
+	window.Pack(introFrame, ui.Pack{
+		Side:  ui.N,
+		FillX: true,
+	})
+
+	lines := []struct {
+		Text string
+		Font render.Text
+	}{
+		{
+			Text: "About",
+			Font: balance.LabelFont,
+		},
+		{
+			Text: "These are the files embedded inside your level data. When\n" +
+				"a level is Published, it can attach all of its custom doodads,\n" +
+				"wallpapers or other custom asset so that it easily plays on\n" +
+				"a different computer.",
+			Font: balance.UIFont,
+		},
+		{
+			Text: "File Attachments",
+			Font: balance.LabelFont,
+		},
+	}
+	for n, row := range lines {
+		frame := ui.NewFrame(fmt.Sprintf("Intro Line %d", n))
+		introFrame.Pack(frame, ui.Pack{
+			Side:  ui.N,
+			FillX: true,
+		})
+
+		label := ui.NewLabel(ui.Label{
+			Text: row.Text,
+			Font: row.Font,
+		})
+		frame.Pack(label, ui.Pack{
+			Side: ui.W,
+		})
+	}
+
+	/////////////
+	// Attached files table.
+	fsFrame := ui.NewFrame("Doodads Frame")
+	fsFrame.Resize(render.Rect{
+		W: windowWidth,
+		H: btnHeight*perPage + 140,
+	})
+	window.Pack(fsFrame, ui.Pack{
+		Side:  ui.N,
+		FillX: true,
+	})
+
+	var fileRows = []*ui.Frame{}
+
+	// Get the file attachments.
+	files := cfg.Level.ListFiles()
+	for _, file := range files {
+		file := file
+		row := ui.NewFrame("Row: " + file)
+		label := ui.NewLabel(ui.Label{
+			Text: file,
+			Font: balance.UIFont,
+		})
+		row.Pack(label, ui.Pack{
+			Side:    ui.W,
+			Padding: 1,
+		})
+
+		delBtn := ui.NewButton("Delete: "+file, ui.NewLabel(ui.Label{
+			Text: "Delete",
+			Font: balance.SmallFont,
+		}))
+		delBtn.SetStyle(&balance.ButtonDanger)
+		delBtn.Handle(ui.Click, func(ed ui.EventData) error {
+			if cfg.OnDelete != nil {
+				if cfg.OnDelete(file) {
+					row.Hide()
+				}
+			}
+			return nil
+		})
+		cfg.Supervisor.Add(delBtn)
+		row.Place(delBtn, ui.Place{
+			Right: 4,
+		})
+
+		fileRows = append(fileRows, row)
+	}
+
+	for i, row := range fileRows {
+		fsFrame.Pack(row, ui.Pack{
+			Side:  ui.N,
+			FillX: true,
+			PadY:  2,
+		})
+
+		// Hide if too long for 1st page.
+		if i >= perPage {
+			row.Hide()
+		}
+	}
+
+	/////////////
+	// Buttons at bottom of window
+
+	bottomFrame := ui.NewFrame("Button Frame")
+	window.Pack(bottomFrame, ui.Pack{
+		Side:  ui.S,
+		FillX: true,
+	})
+
+	// Pager for the doodads.
+	pages = int(
+		math.Ceil(
+			float64(len(fileRows)) / float64(perPage),
+		),
+	)
+	pagerOnChange := func(newPage, perPage int) {
+		page = newPage
+		log.Info("Page: %d, %d", page, perPage)
+
+		// Re-evaluate which rows are shown/hidden for the page we're on.
+		var (
+			minRow  = (page - 1) * perPage
+			visible = 0
+		)
+		for i, row := range fileRows {
+			if visible >= perPage {
+				row.Hide()
+				continue
+			}
+
+			if i < minRow {
+				row.Hide()
+			} else {
+				row.Show()
+				visible++
+			}
+		}
+	}
+	pager := ui.NewPager(ui.Pager{
+		Name:           "Files List Pager",
+		Page:           page,
+		Pages:          pages,
+		PerPage:        perPage,
+		MaxPageButtons: maxPageButtons,
+		Font:           balance.MenuFont,
+		OnChange:       pagerOnChange,
+	})
+	pager.Compute(cfg.Engine)
+	pager.Supervise(cfg.Supervisor)
+	bottomFrame.Place(pager, ui.Place{
+		Top:  20,
+		Left: 20,
+	})
+
+	frame := ui.NewFrame("Button frame")
+	buttons := []struct {
+		label   string
+		primary bool
+		f       func()
+	}{
+		{"Close", false, func() {
+			if cfg.OnCancel != nil {
+				cfg.OnCancel()
+			}
+		}},
+	}
+	for _, button := range buttons {
+		button := button
+
+		btn := ui.NewButton(button.label, ui.NewLabel(ui.Label{
+			Text: button.label,
+			Font: balance.MenuFont,
+		}))
+		if button.primary {
+			btn.SetStyle(&balance.ButtonPrimary)
+		}
+
+		btn.Handle(ui.Click, func(ed ui.EventData) error {
+			button.f()
+			return nil
+		})
+
+		btn.Compute(cfg.Engine)
+		cfg.Supervisor.Add(btn)
+
+		frame.Pack(btn, ui.Pack{
+			Side:   ui.W,
+			PadX:   4,
+			Expand: true,
+			Fill:   true,
+		})
+	}
+	bottomFrame.Pack(frame, ui.Pack{
+		Side:    ui.E,
+		Padding: 8,
+	})
+
+	return window
+}
diff --git a/pkg/windows/publish_level.go b/pkg/windows/publish_level.go
index 514e162..f39cbf6 100644
--- a/pkg/windows/publish_level.go
+++ b/pkg/windows/publish_level.go
@@ -123,39 +123,7 @@ func NewPublishWindow(cfg Publish) *ui.Window {
 		PadX: 2,
 	})
 
-	// // Collect all the doodad names in use in this level.
-	// unique := map[string]interface{}{}
-	// names := []string{}
-	// if cfg.Level != nil {
-	// 	for _, actor := range cfg.Level.Actors {
-	// 		if _, ok := unique[actor.Filename]; ok {
-	// 			continue
-	// 		}
-	// 		unique[actor.Filename] = nil
-	// 		names = append(names, actor.Filename)
-	// 	}
-	// }
-
-	// sort.Strings(names)
-
-	// // Identify which of the doodads are built-ins.
-	// usedBuiltins := []string{}
-	// builtinMap := map[string]interface{}{}
-	// usedCustom := []string{}
-	// if builtins, err := doodads.ListBuiltin(); err == nil {
-	// 	for _, filename := range builtins {
-	// 		if _, ok := unique[filename]; ok {
-	// 			usedBuiltins = append(usedBuiltins, filename)
-	// 			builtinMap[filename] = nil
-	// 		}
-	// 	}
-	// }
-	// for _, name := range names {
-	// 	if _, ok := builtinMap[name]; ok {
-	// 		continue
-	// 	}
-	// 	usedCustom = append(usedCustom, name)
-	// }
+	// Collect the doodads named in this level.
 	usedBuiltins, usedCustom := publishing.GetUsedDoodadNames(cfg.Level)
 
 	// Helper function to draw the button rows for a set of doodads.