Spend one boost tank wisely across ice, rock and slush
This app is a race down a frost canyon, and the running is not your job. The sprinter keeps her own pace along the track without any help from you. What you hold in your hands is her boost: a small tank that never refills, burning away for as long as you keep a finger on the screen. Lift off and the burn stops. Hold too long and there is nothing left for the stretch that mattered.
The canyon is what turns this into a decision rather than a reflex. On the pale ice, boost pays off enormously — a short burn there carries her a long way and opens real distance. On bare rock the same fuel barely registers, nudging her forward for a fraction of the gain. And in the slush bands it does nothing at all; every drop spent there is simply gone. So the track becomes a budget problem written in terrain. You read the ground coming towards you, you decide where the tank is worth opening, and you accept that the fuel you spend early is fuel you will not have at the top of the final rise.
Ahead of her runs the pacer, and the crystal finish line is the only thing that settles the argument. Beating it is rarely about one long, greedy hold. It is about recognising the ice stretches that genuinely repay you, keeping your thumb off the glass through the rock, and refusing to waste anything on slush even when the pacer is pulling away and the temptation to burn is strongest. Patience through the cheap ground is what funds the sprint through the expensive ground.
Twelve levels lay out the canyon in different arrangements, each one a fresh question about where the fuel belongs. Some tracks put their ice early and dare you to spend it all at once. Others hide the best returns behind long dull stretches of rock, so the run becomes an exercise in holding back. A route you failed by metres often opens up the moment you move a single burn to a different patch of ground, and that small realisation is the heart of the game.
The controls are a single hold, so nothing stands between you and the choice itself. Everything you learn, you learn by watching where the boost went and where it should have gone — by the fourth or fifth attempt at a track you stop reacting to the canyon and start planning across it. Pick a line, divide the tank, and see whether your budget holds all the way to the crystal.