The supermarket is a mess. Items are dumped all over the floor, and your job is to grab each one, figure out which aisle it belongs to, and drop it on the matching colour-coded shelf. Aisles are themed, so once you know that milk heads one way and apples head another, you can move fast.
Every item you sort correctly pays out cash. You spend that cash between runs on upgrades: permanent Keys that boost things like how much you can carry and how fast you move, plus active Abilities you trigger on the fly. Keep sorting and the store keeps growing, with shelves that stretch farther than you would expect.