Is it worth buying?
Hmm. Maybe. I think in some ways, they released an unfinished game. I'm a little disappointed that certain parts of the story that were rather important was turned into DLC. That's not something I condone at all.
Are you enjoying it?
It's enjoyable. However, what I seek in Final Fantasy games are an emphasis on story and music. I wasn't disappointed with the soundtrack, but the story was a major letdown.
Does it fall short in anyway?
Having beaten the game, I've spent a lot of time discussing it with others. It's not a bad game at all, however, it falls short in many areas. Like I mentioned earlier, the story is probably the biggest letdown. You can beat it in less than twenty hours if you do nothing else. The open world formula isn't done very well either. It may be a bit unfair comparing it to Witcher 3, but many of the sidequests are repetitive and do nothing for the story or add anything of worth to it.
Do you regret buying it?
Not really. *shrug*