Number Ferry: River Sum Puzzle

An old ferry, a bundle of letters and a river waiting to be reconnected. Join Mara on a journey through five riverside towns, where every passenger carries a number and every crossing needs an exact total.

Number Ferry is a calm arithmetic logic puzzle. Choose who boards, check the sign and think one trip ahead: a group that fits now can leave an impossible remainder on the bank.

How it plays

• Click numbered tickets to board passengers, then cross the river.
• The load must match the sign exactly, without going over the seats.
• Balanced boats split the load across two equal decks; route boats follow a list of stops, each with its own load.
• Undo, pencil marks and the number-line helper are always there. No timer.

150 crossings, five towns

Three boat types across five chapters, with a letter from Gran waiting at the end of each one. A daily crossing waits every day, and 90 twilight crossings add more when you want them.

Controls (PC)

• Mouse: click numbered tickets to board passengers, then Cross. Click a boarded ticket to take it off again.
• Keys: Z or Backspace: undo. F1 or H: the rules.
• Enter: Continue on the home screen, or a message's first button (Next). Esc: back / pause; on the home screen it asks before quitting.

The itch.io version

• No ads. No in-app purchases. The full game, once.
• Every help from the mobile version is free and instant, as often as you like: Explain a useful group, Check the remaining journey, Open a twilight crossing and Use the sunset boat for 3 crossings.
• English, Spanish and Brazilian Portuguese: switch any time in Settings. Larger text and reduced motion are there too.
• A 520x960 window that fits a 1080p screen and can be resized. Plays offline, no account.

Credits

Design, code, puzzles and original audio: Crystl Labs. Ferry and dock: Kenney Watercraft Kit (CC0). Type: Baloo 2 and Nunito (SIL Open Font License). UI symbols: subsets of Noto Sans Symbols, IBM Plex Mono and Zen Maru Gothic (SIL OFL 1.1). Made with Godot (MIT). Optional crash reports by Sentry (MIT).