God's Trigger and Enter the Gungeon are free for a limited time on the Epic Games Store. These games normally cost 14.99 euro but for the next seven days you can get them for free. The offer ends on Thursday, August 27.
To get the games, just go to the God's Trigger and Enter the Gungeon pages on the Epic Games Store, and click the "GET" button. Once you get the games, they will be yours forever.