The concept seems fun, but I had too many issues with odd hitboxes when playing through the game. Whenever an enemy hit me, I would get sent into the air. Whenever I let go of the shopping cart, it would push me back and was near impossible to navigate around. When an enemy was coming at me, I let go of the shopping cart when they got close, and it launched them out of the map. In another similar situation, my shopping cart ended up above me, floating in the air.
It's a pretty neat concept, but it could do with some bug-fixing and more mechanics. A way to combat the other shoppers would add so much fun to the game.