If you played more than an hour or so you probably can't return via that avenue.
2 hours. Which should be enough time to notice the game isn't 1:1 5e rules
Steam refunds are usually not that precise about gametime. I've returned a game I played for 3 hours in the past. 3-4 hours will probably be fine for a return as long as you've only had the game for a day or two.
