This is a good game. Not more, not less. Good graphics, decent mechanics, and an open-world feel that allows you to progress the main story at your desired speed are the highlights.
The fight mechanics of the game are decent, and pretty enjoyable. Nothing like flying around a small battlefield warp striking everything until it dies. That being said, fight mechanics are, for the most part, pretty repetitive, yet I never got tired of fighting in my playthrough.
A few parts where the game struggled to win me over were:
1. Travel mechanics. Regardless of how many side-quests you want to complete, you'll spend ~60% of the game driving, riding in a car (or a train or a boat), or just walking to your destination. Your sprint speed isn't fast enough compared to your walking speed, and your stamina runs out too quickly. I ended up having to dodge roll across the map.
2. Time mechanics. The days are so short (which is fine), but the time it takes to travel anywhere ruins it! Oh, and by the way, if you try to walk or drive during the night before level 30, you'll get destroyed by incredibly tough monsters.
3. World Development. There was so much potential that I felt was not achieved. There are 3 different "continents" with separate cultures, cuisines, and landscapes, and Square Enix attempted to make it "Open World". My problem was I felt I got boxed in to one corner of that world, and didn't get to spend enough time in the "foreign" places. I also didn't fall in love with the places I was boxed into. I never had the feeling that "I wish I could go there in real life", which is something I've felt in so many other FF and Square Enix games.
4. Story/Character Development. You can read in other comments here that the story line was very short, and as such it was very rushed. You're supposed to catch every passing word and subtle reference and piece together the backstory as you go, and I found it very disorienting. The relationship between Noctis and his dad is not explored at all, and could have been such an interesting dynamic to the game. The relationship between the main characters is also somewhat disjointed, and I didn't find it incredibly compelling. Even in the parts of the story that weren't rushed, there were so many questionable decisions. It is difficult to understand who the characters are, and what their motives are. The story in this game feels like it's based off of the Wikipedia synopsis of another game.
All in all, this is a decent game, and I liked it. I really did. But I won't be playing it a second time.