What I Built
ECLIPSE: The Last Day is a narrative puzzle game built for the June Solstice Game Jam. The premise: this is the world's final solstice. Every day brings less daylight. Light is your health and your energy — and the only thing standing between you and the dark is how carefully you spend it.
The game runs entirely in the browser, no install required.
▶️ Play it here: https://eclipse-delta-five.vercel.app/
🎥 Demo video: https://www.loom.com/share/0ec5e5a8a4634b5c8103bccd3f8294ff
The Idea
The June solstice is the day the sun stands still — the hinge point between more light and less. I wanted a game where that idea wasn't just a backdrop, but the actual mechanic: every single day in-game, your light budget shrinks. Fewer orbs to collect. A shorter sun. A longer shadow.
Hidden inside that shrinking daylight is a second story — about Alan Turing, born this same month, and the machine he built to find order inside something designed to resist it. Each day, walking into the dark opens a Memory Chamber: an Enigma-inspired cipher room where you decode a scrambled word (Caesar shifts and Atbash reversals, dressed up as turning wheels) to recover a memory fragment. Solve all seven and you've reassembled a quiet, fictionalized elegy for a man whose work outlived the credit he was given in his lifetime.
Your companion through all of this is Ada — named for Ada Lovelace — who reacts to your light level, nudges you toward orbs when you're fading, and offers hints on the ciphers (at a cost: hints cost you light, so even asking for help is a real tradeoff).
How It Plays
Move with arrow keys / A·D (or tap left/right on mobile)
Walk into gold light to refill your light meter
Each day has fewer orbs and a lower sun — the difficulty curve is the theme
Walk into the dark gate each day to enter a Memory Chamber and solve that day's cipher
Survive all 7 days to reach one of 4 different endings, determined by how much light you preserved along the way
Progress autosaves to your browser so you can continue later
What's Under the Hood
Pure HTML5 Canvas — no game engine dependency, runs instantly in any modern browser
A dynamic lighting system where sky color, sun height, vignette darkness, and ambient particles are all derived live from two numbers: which day it is, and how much light you're currently holding
A small from-scratch cipher engine (Caesar + Atbash) generating a new puzzle per day
Local save/load via localStorage, an achievement system, an accessibility text-size mode, and prefers-reduced-motion support baked in
Ada's dialogue runs on a hand-written local language model of her personality — built to mirror the tone Gemini-powered dialogue would have, while keeping the game playable instantly with zero setup or API keys
What I'd Build Next
Given more time, I'd add more puzzle variety beyond substitution ciphers (Turing's actual work involved much richer logical deduction), expand the memory fragments into a fuller narrative, and let Ada's dialogue be fully dynamic and aware of how the player is playing — cautious vs. reckless — rather than just their current light level.
Built With
HTML5 / CSS / vanilla JavaScript (Canvas 2D)
Hosted on Vercel
AI coding assistance: drafted and iterated with Claude (Anthropic), which the jam rules explicitly permit
Built for the June Solstice Game Jam — thank you to DEV and Google AI for hosting it. Happy solstice. 🌅
Top comments (0)