Support

How do I repair a light?

Tap tiles to turn their wires. Connect the power source on the left to the lamp on the right, passing every required relay. You do not need to use every tile.

I'm stuck on a large board.

Advice and tile inspection are free and pause the clock. Check the entry, find the break, then inspect the goal. Undo is free. A hint fixes one tile and counts toward hint records even when the hint costs no coins.

Can I retry?

Yes. After a failed campaign repair, review the board or retry its original layout. Earlier stars and records are preserved. There is no extra charge for failing.

Where is my progress?

Progress and language settings are saved on this device. Cloud sync and in-game transfers between devices are not supported. Deleting the app may remove your save. An unfinished puzzle is not a saved resume session: reopen the stage to start its layout again. Earned stars, records and language preferences are preserved. If saving fails, check the device's available storage.

Android closed test and free access

The Android closed test is being prepared and is not yet available. Accepted volunteers will receive a private invitation after account registration, Google approval and access checks. Twenty single-use Google Play paid-app promo codes have been generated. Do not purchase the game to join this test.

Use the same Google account for the invitation, test opt-in, code redemption and installation. A promo code does not automatically enroll you in the closed test. Wait for your invitation and confirm a zero payable amount before redeeming. If a price or unavailable message appears, stop and contact us. Do not publish your code or account email.

Current code redemption deadline: December 31, 2026 at 23:00 GMT (January 1, 2027 at 08:00 JST). Android 8.0 or later with 64-bit app support is required. Test regions: Japan, United States, United Kingdom, Canada, Australia, New Zealand, Singapore, India and South Africa.

Once invited, please remain opted in for at least 14 consecutive days and play on several occasions. Honest private feedback is welcome; public ratings and reviews are not required. No compensation is offered.

Contact us

Email shigematsu@nagasu-denki.jp. Please describe what happened, the stage number, app version, device model and operating system version (Android or iOS). Share only information you are comfortable sending. Do not include passwords or payment details.