Helix drops you into a small pod clinging to the inside wall of an endless tube. The pod never stops: it races round and round the wall on its own while the tube rushes forward. You don't steer it. The only thing you choose is which way round it goes, and one tap flips that. Every couple of seconds a wall slab comes out of the dark with a single gap cut into it, and your pod has to be inside that gap when the slab arrives.
Tap anywhere to reverse the spin. The camera turns with you so the pod always sits at the bottom of the screen and the tube wheels around it. Gaps are edged with cyan lamps. Get through and you score ten points times your multiplier. Go through near the middle of the gap and you have threaded it, which adds a bonus and pushes your combo up. Golden gems lie in short spirals along the wall, usually on the far side from the next gap. Taking them means going the long way and reversing again in time, so every slab asks the same question: is there time to go round? Sweep a whole spiral and your combo climbs. Let one go by untouched and it slips back a step. Clipping a slab costs a shield. You get three, or two on Hard.
After about twenty seconds, or 100 points, the tube lights turn red and spines appear: raised red ridges running along the wall that the pod bounces off. Some start right after a slab and force you to hover beside them until they end. Others start late, and you have to race across before they arrive. Orange slabs also start to turn as they come, so the gap you lined up for keeps moving. Chill, Normal and Hard change the speed and how wide the gaps are.
Gatecrash · Airlock · Corridor