How to play

A glowing shape stands between two grey ones. Only it can move – and only sideways.
Drag it so the gap on the left equals the gap on the right. Use the arrow keys to fine-tune pixel by pixel.
Use the zoom (+ / −, two fingers or Ctrl + mouse wheel) to compare the edges up close.
Press “Check” to see both gaps in pixels, the perfect position and your points.

Centre shapes by eye

Centering is a precision game for perfectionists. The shapes on the left and right differ in size and distance from the edge, so the middle of the screen won't help you. Gaps are always measured from a shape's outermost point: on a circle it's halfway up, on a parallelogram at the top or bottom – which is exactly what makes centring tricky.

The deviation counts in pixels: 1 px off still earns 98 points, 4 px about 78. If you need a reliable sense for equal spacing in design, typography or when hanging pictures, this game trains exactly that skill.