Microsoft has released Crackdown 2 for the Xbox One and in a bid to get as many players to enjoy it as possible, they are releasing it for free but that offer might expire soon.
Crackdown 1 and 3 are already playable on the Xbox One but the sequel was never supported for Xbox One backward compatibility program. This has changed now with Crackdown 2, which is now available for free on the Xbox One.
There are two ways to grab the game right now. The first and the preferred one is to go to the Xbox Live Store listing for Crackdown 2 and then grab the game from there. You will have to make sure that you have a valid credit card or payment method aside from Xbox Live Credit, which is the requirement for getting Xbox 360 games, even those which are free.
The second method is to search for Crackdown 2 directly from the Xbox One. It might not show up now but perhaps once the store will update, you can see it directly on the Xbox One.
Crackdown 1 was enhanced for the Xbox One X so it could run at a higher resolution but doesn’t seem to apply for Crackdown 2. You can still enjoy a general higher performance with minor visual improvements for the game on the Xbox One.