Adventure-platformer The End Is Nigh and exploration-adventure game ABZU are both free for a limited time on the Epic Games Store. These games normally cost 11.99 and 15.99 euro but for the next seven days you can get them for free. The offer ends on Thursday, September 12.
To get the games, just go to The End Is Nigh and ABZU pages on the Epic Games Store, and click the "GET" button. Once you get the games, they will be yours forever.