EPURER

Turn the block until both shadows fit. 924 stages, 30 seconds each.

A solid block floats in a bare room. Two walls stand behind it, and each one has a hole cut into it. Turn the block until it fits through both at once.

That is the whole game.

HOW IT WORKS

The block casts two shapes: one against the front wall, one against the side. Turning it changes both at the same time, and that is the difficulty. Line up the front and the side falls apart. Fix the side and the front is gone. Somewhere among the twenty-four ways a solid can sit, there is an angle that answers both.

Pick an axis, pick a direction, and the block turns a quarter turn. Rotation costs nothing. Turn as long as you like, in any order, and take the piece apart in your head as you go. When you think you have it, cast.

The block leaves your hands. Two copies fly, one at each wall. They pass through, or they do not.

WHAT IS INSIDE

924 stages, each one a different solid. Four cells, five cells, six cells. Every stage was checked before it shipped: the shape genuinely fits, the number of solutions is known, and no stage is solved by accident at the angle it starts from.

The stages are ordered by how forgiving they are. Early on, a third of all angles will work. By the end, one in twenty-four. Nothing else changes, no new rules arrive, no mechanic is withheld from you. The room stays the same room. Only the margin narrows.

Thirty seconds a stage. When the clock runs out the block is cast as it stands, so the timer never simply takes the stage away from you. It makes you commit. Miss, and you try again. There is no limit, no penalty, no score to protect. A wrong angle costs you nothing but the wish to see it work.

THE ROOM

Everything is drawn the way a full-size plan is drawn on a workshop wall. Ruled paper, thin lines, one earth pigment for the walls and three for the axes. Nothing glows, nothing celebrates. When the block passes through, the wall simply stops being a drawing and becomes light.

The music is a piano, written rather than sampled from a loop: a walking bass under a running figure, in the manner of a keyboard prelude. As the stages tighten, the key darkens by one step at a time, from Lydian down to Aeolian. You may not notice it happening. You will notice where you have arrived.

PLAYING

Tap only. Two taps to turn, one to cast. It works on a phone held in one hand.

Your progress is kept on the device.

EPURER is French for stripping a thing back to what it is. There is one block, one room, and one right angle. Find it.