https://www.gamespot.com/articles/last-chance-to-get-these-free-xbox-one-games-with-/1100-6457778/

You have just a few days left to claim March's Games With Gold titles before they rotate out in favor of April's new inclusions. If you haven't grabbed them yet, consider this your final warning to get some free games for Xbox One and Xbox 360 with your Gold subscription.

Two games will return to their regular prices on April 1. Those will be Quantum Conundrum and Trials of the Blood Dragon. Quantum Conundrum is actually offered as an Xbox 360 game, but it's playable on Xbox One through backwards compatibility. The final game offered in March, the puzzle-shooter Superhot, will remain free with Gold until April 15. As always, claiming these games before they expire will add them to your collection as long as you're an Xbox Live Gold member.