Phones join with the 4 letters on the TV (or the QR code). The left half of your phone is a stick: it pushes your cart. Carts have momentum, and one bad wheel that pulls to the left. The right half is three buttons. SHOVE lunges the way you're pushing. HOP jumps: over people, onto car roofs, up onto piles. WOBBLE whips the bad wheel around and knocks everything near you flat.
Your points are the damages, in 1997 dollars. Dent a car, total a car, crack a store window, knock a shopper over, flatten a palm tree, bowl a row of carts out of the corral. Big things are worth more.
A shopper you knock over gets up, looks around, and blames whoever's closest. Then they fight, the fight rolls around knocking into things, and anybody nearby joins in. The fight is yours: you get the credit for all of it.
Everything you break spills junk everywhere. Junk lands in piles, piles merge into mountains, and you can drive up them. Sitting on top of the tallest one is worth points every second (THE VIEW). Shove whoever's up there off.
Roll over loose junk and it goes in your basket. Twelve things and your cart stands up: MECHACART, for nine seconds. Twice as big, legs, and every SHOVE is a STOMP. When it wears off the basket dumps into a new pile. Carts that ram you hard enough tip you over and spill your basket.
Five rounds (or three). The most damages: CART OF THE YEAR. Keyboards: WASD with F G R, or IJKL with H Y U. Esc pauses. The store PA will keep you posted.