I have some PTSD because I did work as a cashier on retail for Christmas (in the toys section, unfortunately) and I know that experience all too well.
The music indeed reminds me of those retail days where I had this chill music blasting, while dreading every single second I spent picking up toys and clothing; or having to call the supervisor because the POS just crashed.
If you want to experience the vibe of what it is to do this for real, the music seals the deal.
I have a slight issue to pick with the graphics. When I was selecting the options to lower the graphics quality to the lowest (because, uh, my GPU is a toaster), I reached Medium and the back button moved. I had to move the mouse to the left to reach Low.
Veeeeeery small issue but it’s the kind of detail that might get annoying in UI/UX work. But nothing than setting the width to the largest string wouldn’t solve.
Also… idk if it was me, but were these the collision shapes for the shoppers? 
On that same topic… why soldiers? Probably they also need to buy gifts, they also have families.
And, this is a very humble personal opinion, as a first timer outsider to game jams and gamedev in general: It felt like a mod for a much larger AAA game. Why? Because I felt a disconnect between the absolute pristine detail that Unreal is capable of… and the more arcadey-fast paced fun of the game. It felt like a modded FPS. That’s how I’d describe it.
It’s not bad per se, but it’s the first game I’ve played that I had that feeling. Which is weird considering you folks did most of it yourselves.
That disconnect between aesthetic and theme, it made me a bit confused. The rest? No problem. Pretty good and solid concept that I can approve it’s so real it’s a Retail Simulator. We had calms and storms every single day.