12. It was just bad. The battle system sucked. The main character sucked. I don't think there were any good minigames either (didn't play long enough to find out maybe).
Haven't played 15 so, but it looks bad. 13 wasn't great, but was better than 12. 11/14 I'd say were worse than 12 since I don't like MMOs, but I also don't count them as mainline FF games, despite SE doing so.
Bet Shiken that COD would outsell Battlefield in 2018. http://gamrconnect.vgchartz.com/post.php?id=8749702