Foldline

Fold miniature bridges, deliver nine letters and bring a village to life—using your hands.

Comment

Inspiration

A bridge can become a staircase with one fold. Foldline builds a puzzle around that change: deliver nine letters by folding miniature paths in three dimensions, then bring their village back to life.

The goal is a short, seated game with an obvious purpose. Each solved route restores a house and reveals its resident's letter, so progress changes a place the player can return to.

What it does

Connect the golden path to the doorway. Aim at a numbered hinge, pinch, move to preview a fold, and release to snap to a legal position. Folding one panel moves the connected panels beyond it, so a useful change at one hinge can turn the rest of the route in a new direction. Both the endpoint and doorway orientation must match.

The first route needs one upward fold. When it connects, the courier crosses automatically, a house lights up, and a letter appears. Labelled fold controls offer another way to act. The first puzzle exposes five main VR actions; paths, settings and help stay behind Menu.

There are three ways to keep playing:

  • Complete nine authored routes to restore the village and collect nine letters.
  • Replay completed routes against best-fold targets.
  • Return for a daily route from a finite 24-variant rotation. Completing routes on seven distinct UTC dates adds seven permanent garden pieces. Missing a day does not remove earned growth.

Progress and preferences save in the same browser when local storage is available. If saving is blocked, play continues with a clear notice. The public game is free to open and needs no account, paid API or backend.

Why spatial depth and hands matter

The player changes the route itself. Connected panels rotate through three-dimensional space, and their position and orientation determine whether the courier can reach the doorway. A continuous fold preview makes the consequence visible before release.

Foldline is designed around a seated miniature and hand input, with no virtual locomotion. Desktop mouse, touch and keyboard controls provide a way to try the same puzzles without a headset. Physical seated reach and hand feel still need Quest testing.

Ways to play

There is no timer. Hints, undo, high contrast, larger controls, reduced motion and optional sound let players adjust the experience. Optional head-direction selection activates a VR control after a deliberate two-second dwell. Looking away cancels selection, and a held look fires once. After a menu changes, the player must look away before selecting its replacement controls.

This uses head direction, not eye tracking, and requires voluntary head movement. These options have emulator coverage; they have not been evaluated with disabled players.

How it was built

TypeScript computes the connected panel transforms and validates the route's endpoint and orientation. A solution search supplies hints from the current arrangement. Meta's Immersive Web SDK, WebXR and Three.js render the village and handle immersive input. The village geometry, courier and sounds are created in code; repeated house parts use instanced rendering.

The project was developed during the competition window for the Gaming track and New Experience division.

Challenges and lessons

Direct manipulation needed a clear distinction between previewing a fold and committing it. The implementation previews continuously, snaps on deliberate release, and cancels an unfinished gesture when tracking or session visibility is lost.

The initial controls also competed with the puzzle. Reducing the first route to five main actions made the immediate task clearer. Head-direction selection needed its own safeguard so holding a look could not activate a newly opened menu item.

Validation and launch plans

October 15 validation passed 83 automated tests and a production build. The tests exhaust all 717 legal arrangements across the nine campaign routes and 24 daily variants, checking that each hint leads to a solution in the fewest legal folds. Save recovery covers malformed records, duplicate rewards, blocked storage and daily rollover. Browser checks verified recovery, reloads, keyboard-safe menus and a 360-pixel layout.

Earlier October 5 coverage includes 16 simulated-hand checks, 11 head-only checks, browser completion of all nine routes and seven date-controlled garden rewards. Date-controlled reward tests establish behavior, not measured player retention.

The 1:35 public demonstration contains labelled IWER emulator and desktop gameplay, with English captions. No physical Quest testing has been completed. Quest frame rate, real tracking, stereo readability, seated reach and comfort remain unverified.

Target launch date: September 29, 2026 for the public WebXR prototype, which is already live. Further release decisions depend on physical Quest validation; no Meta Horizon Store launch date is committed. The next milestone is hands-only Quest testing of onboarding, a later puzzle and interruption recovery, including measurement against the judging rubric's 60 fps minimum. Findings will guide control sizing, pacing and future puzzles.

Try it

Open Foldline and choose Enter the village. On the first route, fold the numbered hinge upward and watch the delivery. Then explore Menu for paths, settings and help, or try the daily route. In a WebXR-compatible headset browser, choose the in-game VR entry control; the desktop preview is also available.

Built With

Share this project:

Updates

Submission history