Let’s get you playing.

Not sure when to press?

Read the one-minute guide. Compare each stream with exactly N steps back. Press both for two matches; press neither when nothing matches.

No sound?

Turn up media volume, check your headphones, and press Sound check. If it fails, check your connection and try again. Keep the page in front while playing. A round needs both sound and the visual grid.

Where did my result go?

This browser edition keeps the current round in tab memory only. Reloading, closing the page, or leaving it clears that result. There is no sign-in, cloud save, or shared leaderboard here.

Found something confusing?

Email help@xnback.com. Tell us your device, browser or app version, N level, what you expected, and what happened. Please do not send passwords, sign-in codes, or other private account details.

Sign-in and account help

Use the same sign-in method you used to create your account. With Sign in with Apple, use the same Apple Account. Apple may hide your email behind a private relay address. If you still cannot get in, contact us. Do not create another account to recover existing progress.

Delete your account

In the iPhone app, open Settings and choose Delete account. Type DELETE and complete the sign-in confirmation. Deletion continues on the server after you leave the screen. It removes your account, progress, and unsent rounds on that device. Simply deleting the app does not delete your account.

If you cannot sign in, email help@xnback.com to request deletion. We will check that the account is yours. Tell us if your request concerns an iPhone account or an account from the earlier browser app. See Privacy for backup and archive details.

Looking for the old browser account?

The new browser game has no sign-in or saved history. Your earlier browser account does not become an iPhone account automatically. Contact us for help with its data.