Prism Riddle is a browser-based optics puzzle game for players who enjoy spatial reasoning and experimentation. Move and continuously rotate mirrors, lenses, prisms, beam splitters and filters to illuminate stone gates with the right color and energy. An adjustment near the light source can change the entire route, so the challenge is making the tools work together. The campaign contains 80 original levels across eight chapters. Try the first three levels and a free optical workshop before buying the full campaign. No account or download is required. Play at your own pace with no countdown, undo/redo, hints and precise angle controls. Supports mouse, touch and keyboard, with English and Chinese interfaces. Progress is saved in your browser.