steam says that a exe file for the demo is missing so it does not work

Pressed B on controller or escape after opening the shop and weapons tab and can't exit the menu.

Same exact game and sounds. If this isn't made by the same dev, this could get sued. lol.

I don't have enough money available for this game, not enough.

Game is fairly straightforward but wondering if you had any sage advice? ( particularly in the area of what to buy first ) Thank you!