Spectral Horn

Spectral Horn is a 2D optical physics puzzle game handcrafted for js13kGames 2026, engineered strictly to fit within the 13 kB zip limit with zero external libraries or assets.

In 1666, Sir Isaac Newton stuck a glass prism into a sunbeam and proved that white light is a chaotic rainbow party. Naturally, we asked the only logical follow-up question of modern science: What if, instead of a prism, we used a unicorn horn?

Guide white beams into the crystalline horn of a celestial unicorn, disperse light across physical wavelengths using real Cauchy dispersion, and exploit total internal reflection to bounce rays around obsidian shields. Every bounce and refraction is calculated analytically in real time across 17 handcrafted levels.

Controls: Drag the unicorn to move, rotate the orbit ring to aim, and use the step buttons for 0.5° micro-adjustments until the spectral sensors lock at 100%. Full touch and mobile support with vertical finger offset.

Created by Filip Paulů — https://paulu.cz/