: When you go to the Free Games With Gold section of the Xbox360, it also shows
: the free games for the Xbox One. This is clearly meant to encourage you to
: buy a Xbox One. And there's nothing wrong with that.

: However, if you click on one, it loads a Xbox One interface (sorta). The free
: game for the Xbox One now says "Get This Game". Clicking it
: causes a short load icon and the text changes to "You Have This
: Game."

: If I'm understanding this correctly, this means that Xbox 360 users can
: "buy" free Xbox One Games (of the month) via their 360. Thus
: allowing them to already own the game once they purchase a Xbox One and
: attach their account to it.

: Xbox.com ALSO gives you this option, regardless of which Xbox console you
: own.
: http://www.xbox.com/en-GB/live/games-with-gold?xr=shellnav

: It needs to be noted that I have already attached my account to a Xbox One
: via my former room-mate's console. So that might have something to do
: with my account having these options. But if you only have a Xbox 360 (or
: X1), then it's worth checking out at least. Better to own these games when
: they are free then when the sale ends. ;)

As others have noted, Games for Gold behaves differently on the two platforms; on the Xbox One, you 'own' the game as long as you have Xbox Live Gold. (On the 360, you only get a 2-week window to download the game, but once it's downloaded, it's yours, regardless of what services you have or don't have.)

So - what you've noticed is planned behavior. :)