Gamified Supermarket Shopping - Demo Game - Unity 3D

We want to build a 3D game demo, where the player enters a supermarket and pick stuffs he wants. The player will not use a shopping cart to add products. Instead the player add items to his Military bag. The theme should be like a FirstPersonShooter game, but the user will either pick items with hand or shoot at a product at a long distance to add it to the shopping cart.