Borderlands: The Handsome Collection is currently free to download for the Xbox One in Europe. To grab it, head over to the Microsoft store and you can add it to your account.
It's unclear why the title is available for free and, given that it has been available for a few hours now, it doesn't seem to be a mistake. The most likely explanation is that it is part of the Free Play Days, as pointed out in this NeoGAF post. Microsoft hasn't officially announced that Borderlands: The Handsome Collection is part of Free Play Days, however.
Additionally, it doesn't look like it is available to download for free on the US Microsoft store. Access to games that are part of the Free Play Days promotion is usually revoked after a specified period, so we wouldn't get too attached to that digital copy of Borderlands: The Handsome Collection.
Borderlands: The Handsome Collection is an upgraded compilation that features Borderlands 2 and Borderlands: The Pre-Sequel. In GameSpot's review it was awarded an 8/10.
"Let's be clear: You don't have to be Handsome Jack's number-one fan to appreciate Borderlands: The Handsome Collection. But even if you're not, you will still find an impressive archive, chock full of dozens upon dozens of hours of laughter and exciting combat," said Cameron Woolsey.
"Even considering issues presented by Borderlands: The Pre-Sequel, The Handsome Collection is still a great compilation, allowing you to witness not only Jack's tale, but play a major role in shaping the history of Pandora itself, along with its lonely moon. And that is a story that Marcus may gladly tell again someday."
Read the full Borderlands: The Handsome Jack Collection review here.