Betano.

A single white beam leaves the emitter and travels across a neon optics grid. On its own it reaches nothing. Everything that happens next is your doing: you drag glass prisms and mirrors onto the free cells, tap them to rotate, and watch the light bend, fold and break apart into red, green and blue. That is the whole idea of this puzzle. White light is not one colour but three, and your job is to take it apart and deliver each part where it belongs. A red crystal only wakes to a red beam. Green answers only to green. Blue waits for blue. And the board does not clear when you light them one after another — every coloured crystal must be burning at the same moment, in the same still arrangement of glass. One beam in, three branches out, all of them arriving at once. So you learn to think in angles. A mirror turned a quarter and the whole picture changes: a branch that was sliding uselessly into a wall now cuts straight across the grid and finds its crystal. A prism moved one cell sideways splits the light earlier, giving a branch the length it needed to reach the far corner. Sometimes the piece you were missing was never a new piece at all, only the one you already had, facing the other way. There are thirty boards, and they open up slowly. The early grids let you feel how the glass behaves — how a prism divides, how a mirror folds a line back on itself, how much space a beam needs before it can be bent again. Later the free cells grow scarce, the crystals sit in awkward places, and the single beam has to be stretched further than it looks able to go. The pieces on the board stop being a toolkit and start being a puzzle of their own: not what to use, but where the one correct place for each of them is. Nothing here is rushed. There is no timer leaning on you, no penalty for turning a prism twenty times to see what it does. You can take a board apart completely and start the geometry again from the emitter. The pleasure is in the moment the last angle lands — three colours locked in place, every crystal lit, the grid finally quiet — and in knowing you found that arrangement yourself. A calm, bright game of light and geometry, for anyone who likes to sit with a problem until the shape of it clicks.