Solstice — A Light-Routing Puzzle Game

Play it here: 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.