Majority of what I wanted to say is already covered in Part 1 and 2, which go through almost every aspect that I could think of, but now I will get down to the business, as in talking about what works and what doesn't, the pros and cons and more.
Story
I feel it is safe to say that if you are expecting a story that plays similar in style to any of the older FF games, then just tailor your expectations, because FFXV is vastly different in this regard. It doesn't offer the same cutscene laden story and narrative that the past FFs are known for, however, it doesn't mean the game lacks any story at all. There is a story, yes. However it plays out in a way that it feels like a disjointed mess where the plot doesn't make sense at first. A lot of major plot related events also happen offscreen which is really one of the worst part of this story. I wouldn't have cared much if they kept this type of story telling style but the way they completely skip some of the major character arcs is completely unbelievable and I can't help but feel disappointed. It feels like a game that was cut from multiple points to try to present a coherent story line but it fails to do that successfully and becomes more of a Frankenstein monster.
Which is a shame to say the least, since it is clear from playing the game that countless man hours and a lot of careful design work was put to create the open world portion of FFXV, which is really well made. It is one of my favorite open world in any game, and definitely tops some of the past FF open world design for me.
But there is a silver of hope for the story, which is closer to the end of the game, when story takes the front seat. By better, I don't mean to say it suddenly becomes TLOU in story telling, but compared to the usual JRPGs, I'd say it works much better. It is also at that point that the game begins to follow the narrative design of the past FF games, which then leads to the end. There are some obvious leaps of logic to reach the conclusion (like any FF game) but I will say this, once we reach the end of the journey, the way the ending is laid out and how it plays out makes it one of the most memorable ending for me. Atleast it left me with a satisfying feeling unlike MGSV.
The Open World
If I had to compare any game to FFXV's open world, it would be Dragon's Dogma. It is certainly not Witcher 3 but it isn't some boring JRPG tier open world either. It is actually really well made where each of the monsters are carefully placed in a habitat that suit them. And talking about monsters, there is a HUGE variety of monsters in the game that are taken from all the classic FF games. There are so many of them and they are scattered around the world map that it is easy to miss like 50% of them if we just play the main story. There are mini boss fights throughout the world map and it is easy to stumble into a challenging encounter when exploring the world map.
The open world is absolutely gorgeous, but not without its flaws. The visuals aren't consistent and while there are times when the game looks absolutely breathtaking, we also have times when it looks downright ugly. This mostly falls to the engine and the lighting tech, which powers it. Lighting really makes or breaks the game's visual and while it is clear that the engine is highly capable, the inconsistency could have perhaps worked better when they could craft a linear experience where every scenario is personally tweaked. Still, the dynamic open world mechanism with a day and night cycle and weather system makes for some great road trips around the world map.
Post-game Content
If there is one area I feel like FFXV has succeeded, it is the amount of content that it offers. There are dozens and dozens of hunts that are given by restaurants/shop owners throughout the world map. Each of them offers a different variety of hunt that involves monsters that are closer to their habitat. So we don't randomly start a hunt and find a reptile creature in a desert, for example. There are also more than dozen of mini boss fights and then secret boss fights, that are also given through the hunts.
I have already talked in detail about the sidequests in my Part 2 impressions so please read that if you want to find out more. I will say that not all of the sidequests are fetch quests. While it feels like majority are, I highly recommend to do the quests that urge to explore the world map if we haven't personally discovered that location yet. Also while the fetch quests from generic NPCs don't offer much narrative, there are some that do. There was a quest from Gladious where I had to go to the volcanic mountain and steal a Zuu egg. It was fairly basic but it also was the first time I had discovered that location.
Aside from the hunts, there are dungeons that are never repeated from what I have played, each of them is different from the other and while some might be short, they all contain a tomb that rewards the player with a special Kings arms. I highly recommend to find all 13 of them before reaching the end of story. I can't say much about the secret stuff but there was one dungeon discovered recently so this gives me hope there are more after post-game.
I will now give a pro and con along with a conclusion.
Final Fantasy XV is definitely fit to be called a mainline FF game. But it unfortunately comes tied with 10 years of baggage, that lets it down, especially in the story department. The developers have crafted an exceptional open world and one of the best combat system in my eyes. But there are little flaws in both that stop them from being perfect. That said, my biggest disappointment with the game is the story and how the narrative plays but it is also one of my favorite FF ending, strange, right? Well, I don't know what to say aside from that the ending will properly convey our sense of journey and offers a conclusion that all depends on whether you enjoyed this journey through your friends or hated it. If you hated the majority of the game, chances are, you might hate the ending as well.
Pro
Battle system
Open World
Camping and the whole road trip.
Magic.
Monster Variety
Character and skill progression.
Ending
Technical Performance
Story.
Fetch quests.
Lack of memorable side characters.
Load times.
Overall, without the ending and post-game content, I would rate it 8/10. If we count the ending and post game content, it is a solid 9/10 for me.
The million dollar question
Is it worth it for the Versus fans?
Short answer: No.
Long answer: The game has been designed in a way where the gameplay takes the front seat through the majority of the game while story is likely in the trunk of that car. It still plays and feels like a FF game but I can't help but feel like the narrative is a mess like FFXII, which was another game with director change in mid-development.
Is it worthy of a mainline FF game
Yes. It sure does a lot of things that were needed by the series and breaks from the traditional formula. I can't help but feel it should have been its own game instead of being tied to Versus XIII.
Is it better than FFXIII?
Without any doubt, yes. The major issue with FFXIII was its linearity which felt restricting compared to the past FF games. FFXV manages to rectify that a lot, and it honestly like the only criticism that they took from FFXIII was the lack of open world. So the game feels like it was designed in this way. But that said, FFXIII had around 8+ hours of cutscenes and we all know despite this all, the story was total shit and the ending made only added to the confusion.