Last year I was able to buy 1 game at self checkout since it wasn't in a security case at another location. It's when I went back to a regular register with games in the cases that I had the problem of not being allowed to buy them. Normally my local Walmart stores don't check receipts if an item is in a bag but it seems to depend on the worker.
For whatever reason, I have never been able to buy a game at self-checkout. You ask them to get a game out of the glass case, they walk it up to Electronics and get you to pay for it, or leave it up at their check out area while you shop for more. That has just been my experience.
None of us here really had problems. The self-check person is really there to help assist, not monitor 24/7.
Worst case scenario is you show them the price on the app and they let you go.
When I attempted to buy a couple of 3 cent games last year, they made a big fuss before allowing me to...even after they acknowledged the price on the app. Their attitude was "this must be wrong". Again,as I said, I've never been able to pay for a game at self-checkout. They always ask me to pay at Electronics. And no, I don't think I look like a thief.