Crossing

Arrow keys, WASD, swipe, or the pad. On a phone, a tap anywhere on the board hops you forward, which is the only control you need. Left, right and back all work, and going back never raises your score, so retreating costs you time and nothing else. Your score is the furthest row you reached. Every traffic lane is built from one repeating gap wide enough to stand in and long enough to cross, so no lane is ever sealed. The dark edge behind you creeps up while you wait, which is the only thing that argues with standing still.