Epic store: "Any game purchased on the Epic Games Store is eligible for refund within 14 days of purchase (or for prepurchases, 14 days from release) if you have played for less than 2 hours."
Steam: " By clicking the button below to proceed you agree that Valve provides you immediate access to digital content as soon as you complete your purchase, without waiting the 14-day withdrawal period. Therefore, you expressly waive your right to withdraw from this purchase. "