Supermarket Mania, at its core, operates as a time management sim set in a grocery store. Or rather, five grocery stores. With a large 50-stage story mode, players take control of Nikki and must manage time and products to keep grocery stores stocked for customers. Besides just working to keep stores stocked, players have to deal with a competing grocery store. By working with speed and dedication, players earn enough cash to upgrade their grocery stores to better compete with the rival store.

Besides the large story mode, the game also features an alternate "Endless Shift" mode with bonuses, five total shops, and seven different types of customers. Supermarket Mania features over a dozen different products to manage, and over twenty upgrades for the stores.

Gameplay is seen and controlled on the bottom (touch) screen of the Nintendo DSi, and the game is viewed from an isometric angle similar to classic Sims games or old PC strategy titles. The top screen is largely used for statistics and other information.