Gelgit Adası — A 3D Island Game Where Homework Fuels the Boat
Gelgit Adası (Ada) is a 3D island game in which homework effort fuels the play, built for the students of Erkan Ulu Okulları, an Istanbul K‑12 school. It runs in Safari on the students' iPads, inside the school's homework platform. In production since 26 Sep 2026 as a teacher-only alpha; opening to students is planned.
Watch the Teaser
The parents' teaser (3:11), with Turkish narration and Turkish subtitles.
Footage from the game in development (alpha), captured with synthetic test accounts. No real student data.
The Challenge
Make homework effort, including going back over mistakes, the thing that moves a game forward, and keep play in its place. The learning rules were set with the school's teachers.
Mistakes Still Count
A missed question has to be worth revisiting: watching the teacher's solution and genuinely trying a similar question earn the reward back.
Play Has Limits
Play time is capped daily and the harbour closes during school hours. Study time never counts against the cap.
Safe for Students
No ads, purchases or chat.
Rewards Are Earned
Fuel is written only on the server, and video watches are verified there.
How It Works
A homework platform on the outside, a fishing island on the inside.
Homework Fuels the Boat
A homework question right the first time adds 1 bidon (1 L of boat fuel). A missed one earns it back in two halves: one for watching the teacher's solution video to the end, one for a genuine try at a similar question.
Nevin Kaptan at the Harbour
An islander who suggests each student's unwatched solutions and opens the school's video gallery inside the game.
Word Fish
Fish ask the meaning of English words from the teachers' weekly list; a word counts as learned after two first-try answers in a row. Juveniles and egg-carrying fish go back to the sea.
Fishing and Coins
Fishing earns coins for gear and boat paint. Answering word questions counts as study time, not play time.
Teacher Panel
Study minutes by kind, word progress and lesson results, with editors for announcements, the word list, cinema films and science lessons that Claude drafts from the teacher's slides. Play minutes stay out of class views.
Built for iPad
Runs in Safari inside the school's homework platform, with three quality presets picked at launch, on A13-or-newer iPads.
Inside the Game
In-game captures and the teacher panel. Select any screen to open it at full size.
The World
Frames from the teaser. Every shot is in-game footage.
Engineering Highlights
A game economy that has to stay honest, running on the students' iPads.
- Touch port of an open-source WebGPU game — the open-source Tidewater game (MIT) was ported from keyboard and mouse to iPad touch, with three quality presets picked at launch; it runs on A13-or-newer iPads.
- Server-authoritative economy — a background worker is the only writer of fuel, through an idempotent ledger. The game API (FastAPI) uses its own Postgres role, which cannot mint fuel.
- Verified video watches — checked on the server: 90% coverage, at most 1.5× speed, page visible, end reached and a wall-clock check. In simulation, 0 of 4,000 honest watches per network case were rejected.
- Contract-first build by AI coding agents — 17 parallel tracks working from written contracts, with a scripted WebGPU play-test lab: the first production release came two days after the build started, and new features have shipped dark behind flags since.
Role: Savaş Tutumlu is the product owner and lead developer. He set the game's direction and learning rules with the school's teachers, directed and reviewed the build by AI coding agents (Claude Code agent teams working from written contracts), tested on iPad and approved each production release.
Who Can Write Fuel
+------------------------------+
| Safari on iPad |
| WebGPU game client |
+--------------+---------------+
|
v
+------------------------------+
| Game API (FastAPI) |
| own Postgres role: |
| cannot mint fuel |
+--------------+---------------+
|
v
+------------------------------+
| Postgres |
| idempotent fuel ledger |
+--------------+---------------+
^
|
+--------------+---------------+
| Background worker |
| the only writer of fuel |
+------------------------------+
Only the server-side worker can add fuel
Technology Stack
Status
- 24 September 2026 — the build starts from the open-source Tidewater game.
- 26 September 2026 — first production release, as a teacher-only alpha in demo mode.
- Since then — new features ship dark behind flags; the latest release went out on 9 October 2026.
- Next — opening to students is planned. Students do not play yet, so no player numbers are claimed here.
Credit: the island, ocean and boat come from Tidewater by Daniel Greenheck, an open-source WebGPU game released under the MIT licence, extended for the school as Gelgit Adası.
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