Solstice — A Light-Routing Puzzle Game

A developer built Solstice, a light-routing puzzle game with a custom ray-tracing engine, dual-spectrum beam physics, and 18 levels across 7 tiers. The game features a CRT terminal narrative with a Turing test theme, optional AI dialogue via Google Gemini, and is deployed as a static site on Vercel.

This is a submission for the June Solstice Game Jam What I Built Solstice is a puzzle game where you place mirrors to guide light beams across a grid. Each level has two modes — SUN and MOON. You toggle between them to route both beams to their targets. Both need to be lit at the same time to win. Click a cell to place a / mirror, click again for \ , again to remove. Right-click removes it. Ctrl+Z to undo. That's the whole mechanic — but the levels get hard fast. There are 18 levels split into 7 tiers. It starts simple one mirror, one beam and builds up to puzzles where you have fewer than 10 free cells and every placement has to count. I verified every level with a Python solver to make sure they're all solvable at the stated par. The game has a terminal with a Bletchley Park theme. You get 3 questions, the AI responds like a trapped wartime consciousness, and at the end you decide if it was human or machine. It connects to the Gemini API if you have a key, otherwise it uses pre-written responses. VIDEO DEMO { https://youtu.be/gqtylwILuJ8 https://youtu.be/gqtylwILuJ8 } Code A light-routing puzzle game with a custom ray-tracing engine, dual-spectrum beam physics, 18 levels across 7 tiers, a CRT terminal narrative, undo/redo, and a star-based rating system. Built with vanilla JavaScript, rendered on HTML Canvas 2D, with audio synthesis via the Web Audio API and optional AI-powered dialogue through Google Gemini. Deployed as a static site on the Vercel CDN. Each subsystem is a standalone ES module communicating through a central game state, orchestrated by a requestAnimationFrame game loop. flowchart LR subgraph Pipeline Core Pipeline direction LR GL "GAME LOOP<br main.js<br requestAnimationFrame<br renderer.draw <br updateUI " RT "RAY TRACER<br raytracer.js<br Dual-pass simulation<br SUN + MOON paths<br Cycle detection" RD "RENDERER<br renderer.js<br 3-pass canvas draw<br Glow + dashes + pulses<br Particle integration" PS "PARTICLES<br particles.js<br emit / burst <br update dt / draw <br Lifecycle management" end GL -- RT -- RD -- PS style GL fill: 1a1a3a,stroke: ffd700,color: ffd700 style RT fill: 1a1a3a,stroke: 4a90d9,color: 4a90d9 style RD fill: 1a1a3a,stroke: 7b68ee,color: 7b68ee style PS fill: 1a1a3a,stroke: 00ff88,color: 00ff88 style Pipeline fill: 0a0a1a,stroke: 333,color: 888 flowchart TB subgraph Systems Supporting Systems direction TB IM "INPUT<br input.js<br Mouse + …Play it here: https://solstice-game-pi.vercel.app https://solstice-game-pi.vercel.app HOW I BUILT IT Vanilla JavaScript with HTML Canvas for rendering. No frameworks, no libraries — just ES modules and the Canvas 2D API. The ray tracer uses grid-based ray marching. Each frame runs twice — once for SUN, once for MOON. Mirrors transform the direction vector: / does dx, dy → -dy, -dx , \ does dx, dy → dy, dx . Cycle detection prevents infinite loops from mirror pairs facing each other. Audio is all Web Audio API oscillators — no sound files at all. The terminal uses the Gemini API when configured, with a system prompt that keeps the Bletchley persona consistent. Levels are hand-designed with increasing wall density. Levels 11-18 went through multiple redesigns after my Python solver kept finding unintended shortcuts. Prize Category BEST ODE TO ALAN TURING ; The terminal is a Turing Test. You talk to something that believes it was a code-breaker at Bletchley Park in 1945. Three questions, then you judge. The dialogue touches on Enigma, ration books, the hum of valves. The ending asks the same question Turing posed — can you tell the difference? Best Google AI Usage The terminal connects to the Gemini API for dynamic responses. The AI stays in character as a wartime consciousness. Without a key it falls back to pre-written dialogue, but with Gemini every conversation is unique.