User blog comment:Zaptroxix/Is Infinity a response from the HD petition ?/@comment-20450721-20131002162515/@comment-1824272-20131003234415

AC6 exclusive to Xbox 360 was because the PS3 was not released at the time, so it was developed for the 360 only. AH was multiplatform because they could do multiplatform. Infinity is PS3 exclusive for reasons unknown but likely because of Microsoft's distaste in free-to-play games.