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title	Lesson 16 · Wrap-up and release

Lesson 16 · Wrap-up and release

Reference checkpoint: node scripts/course-create.mjs --lesson 16 builds this lesson's runnable end state beside your project — compare, never overwrite. See Practice checkpoints.

The game is built. Nobody can play it yet.

This lesson fixes the Back button, bumps the version to 1.0.0, makes a signed APK, and prepares what goes on the itch.io page.

1. Finished screen

2. "Built" and "shippable" are different

Put everything through Lesson 15 on a phone and it runs. Ship it in that state and the first reviews look like this.

Symptom	Cause
Back closed the game	Android default
Version is 0.1.0	never bumped
"This app is from an unidentified developer"	signed with the debug key
You cannot ship an update	you lost the keystore

The last one is the scariest. There is no way back.

3. Check the official docs

Docs	What we take
Exporting for Android	signing, keystore
`NOTIFICATION_WM_GO_BACK_REQUEST`	Back
Feature tags	debug vs release

4. Back — the Android promise broken most often

On the pause code from Lesson 11 we left this note (pause_panel.gd).

Android Back defaults to quit. That is Lesson 16.

Leave the default and the app just quits from any screen. Survive 80 seconds, tap it by accident, and it quits. Open Settings and it quits.

[application]

config/quit_on_go_back=false

Once that is off, we decide. What Android expects is walking back through screens one at a time.

Current screen	Back
Credits	to Settings
Settings	to the previous screen
Playing	pause
Paused	title
Result screen	nothing
Title	ask whether to quit

func _notification(what: int) -> void:
	if what != NOTIFICATION_WM_GO_BACK_REQUEST:
		return
	if _credits.visible:
		_credits.close()
	elif _settings.visible:
		_settings.close()
	elif _over:
		return                                   # do nothing on the result screen
	elif get_tree().paused:
		get_tree().paused = false
		get_tree().change_scene_to_file(TITLE_SCENE)
	else:
		_pause.request_pause()

:::warning Why the result screen does nothing You spent 90 seconds, the score appeared, and Back dumped you to the title — that is leaving without seeing the record.

Here we only accept a tap on the screen to restart. When there is only one thing you can do, leave only that. :::

:::info The final results screen has buttons, Back still does nothing The complete clip shows Retry and Upgrade buttons on the results screen. Those arrived in later updates. The Back rule from this lesson never changed: on results, Back does nothing. :::

:::danger The default on the quit prompt is "go back" If you show a prompt and the dangerous choice already has focus, asking was pointless.

func open() -> void:
	visible = true
	_no.grab_focus()                             # default is go back

Put Cancel on the left, Quit on the right, and give first focus to the left. :::

5. Implement it yourself

5-1. The version lives in two places

# project.godot — the value shown bottom-right on the title
config/version="1.0.0"

# export_presets.cfg — the value baked into the APK
version/code=1
version/name="1.0.0"

version/code is an integer. You cannot upload the same value twice. Forget to bump code to 2 for 1.0.1 and the store rejects it.

The title screen reads the project.godot side.

	var version: String = str(ProjectSettings.get_setting("application/config/version", "0.0.0"))
	_version.text = "v" + version

Manage it in one place. Hand-writing v1.0.0 on the screen will diverge on the next version.

5-2. Keystore — lose it and you are done

Debug builds are signed with the shared debug key Godot makes. Release must be signed with your key.

keytool -v -genkeypair -keystore moonlit-release.keystore \
  -alias moonlit -keyalg RSA -keysize 2048 -validity 10000

:::danger Lose this file or the password and you cannot ship updates An APK signed with a different key under the same package name will not even install. Users have to uninstall and reinstall, and saved records disappear.

Keep the keystore outside the repo, file mode 600 or tighter
Do not write the password anywhere in the repo
Back both up separately
The certificate expiry must be after 22 October 2033, per Google Play requirements

Godot puts the password in .godot/export_credentials.cfg. That is the most important reason .godot/ is in .gitignore. :::

This course repo commits export_presets.cfg and does not commit .godot/export_credentials.cfg. Share settings. Do not share secrets.

5-3. Release build

Export from your blank project with the release keystore from 5-2 selected in the preset (Project → Export, or headless):

godot --headless --path . --export-release "Android"

Name the output for your own app (for example ../builds/moonlit-course-1.0.0.apk), outside the repo. If a build fails halfway, delete the partial output so an old file is never mistaken for a new release.

(Inside a clone of the finished-game repository, the shortcut pnpm android:release does the equivalent for the shipping game — it writes builds/android/MoonlitBeacon-1.0.0.apk and cleans previous output on failure.)

:::danger Do not call Godot export yourself This warning applies inside the finished-game clone: that project builds the Play AAB and the itch.io APK from the same Gradle template, so android:release has to clean previous output and temporarily isolate the IAP plugin so the Play Billing SDK does not mix into the direct-distribution APK. In your blank learner project there is no IAP plugin and no wrapper — the export above is the procedure. :::

Confirm the signature is right.

apksigner verify --print-certs builds/android/MoonlitBeacon-1.0.0.apk

A debug key prints CN=Android Debug. That is wrong.

5-4. Check permissions

aapt dump permissions builds/android/MoonlitBeacon-1.0.0.apk

If there is an internet permission, remove it. This game does not talk to a server. An unused permission is one more reason not to install.

:::info The current builds keep the internet permission At 1.0.0 there was no server, so the permission went out. IAP purchase verification and analytics arrived in later updates, and both need a network — the current presets set permissions/internet=true. The rule stands: keep only the permissions the game actually uses. :::

5-5. On a wiped device

The development device still has save files and old versions.

adb uninstall com.crossplatformkorea.moonlitbeacon
adb install builds/android/MoonlitBeacon-1.0.0.apk
adb shell monkey -p com.crossplatformkorea.moonlitbeacon -c android.intent.category.LAUNCHER 1

uninstall, not pm clear. Look at the same state as a first-time installer. This is where you confirm Lesson 14's cfg.load() does not die on failure.

5-6. Store page

Copy is not what the maker writes. It is what a player reads.

Do not write	Instead
"Enemy system built with custom resources"	"Spirits come out of the dark and chase you"
"Made with Godot 4.7"	(credits only)
"Update coming soon"	(do not write it)

3–5 screenshots. The first one matters most. That is all the listing shows.

Write credits on the page too. Inside the game only, nobody sees them before they download.

5-7. Private first

itch.io can stay Restricted so only people with the link can see it.

Does download and install work
Does page text break
Are screenshots cropped

Then switch to Public. Better than fixing it after it is public.

6. Check that this much is working

Before shipping, rank what you check.

P0: cannot launch, save corruption, cannot progress
P1: win · lose · restart failures
P2: broken UI, sound issues, small balance issues
P3: minor visual issues

Do not ship if any P0 or P1 remains. P2 and P3 wait for 1.0.1.

What	How
A full run	start → three beacons → guardian → gate → results → again
Repeat	ten restarts in a row
Interruption	Home · a call · screen off, then return
Save	best record after quit, first launch after deleting the save
Screen	UI does not overlap at 16:9 · 20:9 · 21:9
Language	text does not clip in Korean or English

Especially these six, press them on a real device.

Back during play → pause (the app does not quit)
Back while paused → title
Back on the title → ask whether to quit
Same with gesture navigation (swipe)
apksigner shows a certificate that is not debug
Uninstall and reinstall, first launch is healthy

7. Break it on purpose

① Leave quit_on_go_back as it is → Back quits the app from any screen. Even after 80 seconds.

② Handle Back on the result screen → You leave without seeing the score.

③ Put first focus of the quit prompt on Quit → Asking was pointless.

④ Redistribute without bumping version/code → You cannot upload the same value.

⑤ Sign release with the debug key → CN=Android Debug is baked in. Switching to a release key later means existing users cannot update.

⑥ Put the keystore in the repo → Anyone can ship an app in your name.

8. Completion checklist

[ ] Back walks through screens one at a time
[ ] The title asks whether to quit
[ ] Version is 1.0.0 in both places
[ ] Signed with the release key (apksigner check)
[ ] No internet permission
[ ] Uninstall and reinstall still works
[ ] Store page copy and screenshots are ready
[ ] godot --headless --path . --import finishes with exit code 0 and no errors in its output

9. Last homework

Back up the keystore. Do it now. The least reversible mistake in this course.
Upload as Restricted and send the link to one friend. Watching it launch somewhere that is not your device is the last test.
Write three lines on what goes into 1.0.1. Thinking after you ship is too late. Write it now and the next one is easier.

After sixteen lessons

In Lesson 1 you opened an empty project. In Lesson 16 you launch a game installed on a phone.

Along the way you reversed things more than once. Lesson 6's bounds widened in Lesson 9, and Lesson 8's hit detection was rewritten in Lesson 9. Lesson 1's brightness was changed twice in Lesson 2.

That is the healthy case. Trying to get it right from the start means you never start. Because we kept it simple, knowing it would change later, the later fix was two lines.

If you take only one thing, take this.

You do not know until you put it on screen.

Lesson 14's beacon bug sat there for five lessons. The moment we printed a number on the result screen, it showed. Lesson 15's settings window only revealed the logo showing through after we rendered it.

"Fine to read" and "fine to run" are different.

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chapter-16.mdx

chapter-16.mdx

Lesson 16 · Wrap-up and release

1. Finished screen

2. "Built" and "shippable" are different

3. Check the official docs

4. Back — the Android promise broken most often

5. Implement it yourself

5-1. The version lives in two places

5-2. Keystore — lose it and you are done

5-3. Release build

5-4. Check permissions

5-5. On a wiped device

5-6. Store page

5-7. Private first

6. Check that this much is working

7. Break it on purpose

8. Completion checklist

9. Last homework

After sixteen lessons

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Lesson 16 · Wrap-up and release

1. Finished screen

2. "Built" and "shippable" are different

3. Check the official docs

4. Back — the Android promise broken most often

5. Implement it yourself

5-1. The version lives in two places

5-2. Keystore — lose it and you are done

5-3. Release build

5-4. Check permissions

5-5. On a wiped device

5-6. Store page

5-7. Private first

6. Check that this much is working

7. Break it on purpose

8. Completion checklist

9. Last homework

After sixteen lessons