That is a bit of a grey area...
It is actually against the law to distribute copyrighted materials other than official means, free or not. This is the basis why Google sent cease and desist letter to Cyanogenmod Team a few years ago, because back then CM team distributed Google apps preincluded in the ROM zip. This is against the law according to Google, who sees the legit distribution of Google apps only via Play Store/Android Market. But then they allowed the devs to distribute Gapps as seperate zip.
I think the rules here in XDA only covers pirating in the means of avoiding payment (because it hurts the developers to do so) but it is allowed to bypass region and device restrictions, if there is no payment obligation.
This is why, here in XDA we see Google Keyboard apks and GEL apks, because they are region and device restricted, but there is no payment obligation to use said apps.
Now back to Asphalt 8... yes it is free to download and free to play, but it still has in-app purchases... so I think it is still not allowed to share it here because it will remove the potential income source for Gameloft. In app purchases will not work on pirated apps, I presume?