A roguelike on your face

A roguelike deckbuilder on a pair of glasses is a bad idea by every normal measure. The display is a postage stamp, the color depth is four bits of grey, there is no pointer and no keyboard, and the only input is a handful of taps on the temple. I built a full one anyway, and the constraint turned out to be the design rather than the obstacle.

The numbers set the rules. Five hundred and seventy-six by two hundred and eighty-eight pixels, monochrome, about twenty-five characters to a line. Everything Balatro needs to show — a hand, the running score, the shop, a wall of jokers — has to fit and read at a glance, on a screen floating in your vision. The suit symbols are not even in the firmware font, so cards fall back to plain letters. There is nowhere to hide a bad layout.

What makes it tractable is the architecture, not cleverness on the glass. The engine is a functional core: an immutable game state, reducers that take a state and an action and return the next one, and a dumb view that turns state into display containers with no logic of its own. The glasses SDK and the Bluetooth calls are quarantined in a thin bridge at the edge. So the whole game — thirty jokers, the real chips-times-mult scoring pipeline, the shop, the boss blinds, save and resume — is headless and testable, and 136 tests run it with no glasses in the loop.

Here is the part I did not expect: the tiny screen made the game better to reason about. A display that small forbids decoration. Every element has to earn its pixels, which forces a clarity about what the game actually needs to communicate that you would never bother to find on a phone, where there is always room for one more flourish. The limit is a design partner, not a tax.

The best reason to build for weird hardware is that it makes you honest. Strip a game down to what fits on glass you can see through, and what is left is the part that was always doing the work.