How to play

There is one control and it is a drag. Press anywhere on the stage and slide your finger left or right, and the puck follows sideways. Your finger does not have to be on the puck, it only has to move: what the puck follows is how far your finger has traveled, so you can steer from any corner of the screen. On a keyboard, hold the left and right arrow keys.

Walls scroll down the field at you, and each one has a single gap. Get the whole puck inside the gap before the wall arrives and you are through. Touch a wall anywhere and the run is over, because there is only one life here.

The puck has a top speed, so the game is really about starting early. A gap far to one side is reachable from anywhere on the field, but only if you set off as soon as you can see it, and the field never stops to let you think.

Threading the middle of a gap is a clean, which doubles your points and starts a streak, and the coin sitting in each gap is exactly the window a clean is judged by. Five clean in a row drops a gem. The points, the coins, the gem and the streak are for the celebration only: what unlocks the cache is rows threaded, and nothing else.

The field quickens and the gaps narrow as the rows pile up, so the same wobble in your thumb costs more the further you get. The gaps drift rather than jump, and no gap is ever further from the one before it than the puck can travel in the time between them.

The moment you reach the goal your reveal is locked in and safe, even if the very next wall gets you. Lifting your finger, switching tabs or leaving the window pauses the run and keeps the puck exactly where it was.

Sound and vibration are both off until you turn them on, with the two small buttons above the stage. Vibration needs its own switch on, and it only buzzes on a phone or tablet that supports it. An iPhone is not one of them for this game: the only buzz iOS gives a web page is one under a finger on a control, and this game is played with a hold rather than a tap, so the button does not appear there.