You get the following for free if you are subscribed to Xbox Live's Gold service:
Xbox One/ Xbox X | S
- The King’s Bird (June 1-30)
- Shadows: Awakening (June 16-July 15)
Xbox 360 (compatible with newer consoles)
- NeoGeo Battle Coliseum (June 1-15)
- Injustice: Gods Among Us (June 16-30)