Games downloaded from Steam
Steam will happily issue a refund for a game for any reason if the request meets the following criteria:
 
1) the request is made within 14 days of purchase
and
2) the title has been played for less than 2 hours
 
For more information visit - store.steampowered.com/steam_refunds/
To request a refund visit help.steampowered.com

Games downloaded from GOG
GOG will happily issue a refund for a game for any reason if the request meets the following criteria:
1) the request is made up to 30 days of purchase