I'll put this in bullet points because I want to get back to playing the game.
-It's very, very pretty.
-The pace of switching between random battles and moving around feels in line with 16-bit games. I personally prefer FFXII's more streamlined system where battles just happen without switching to a special battle mode, but this is pretty seamless. It's closer in pace to, say, Suikoden than to FFVII-IX.
-It's got a Mother-esque system where sneaking up on enemies gives preemptive attacks, which are incredibly advantageous because they nearly fill up the enemies' break gauge. This means you basically do double damage. There are also items you can use to make yourself invisible.
-The dungeon design (so far) seems to borrow from the FFX "keep running forward in a straight line" school of design.
-The character advancement system is basically a combination between the sphere grid and FFX-2's mid-battle class changes. Each character has a separate grid for their various "roles," and you can switch roles mid-battle with the optima system.
-Changing optimas doesn't just change AI, it also changes abilities. So, for example, Serah can only cast cure as Healer, and she can only use attack magic as a Blaster.
-At least as of now, not every character can do every Role, so they all feel unique. For example, only Snow has Defender.
-Despite that, they also feel highly customizable. I found two weapons for everybody by now, and they aren't Sword and Sword+10. One of their weapons will give them stats like Phys Attack: 60/Mag Attack: 40, and the other will give the reverse stats and/or a more balanced stat set. So, changing weapons can basically set which Role you want to emphasize, or if you want an all around character.
-This game avoids the modern JRPG trend of making you watch a cutscene for an hour. When you start the game, you start playing the game basically immediately.
-That being said, there are a lot of intermittent cutscenes between the action. You can pause and/or skip them though. You can also skip all tutorials.
-It is good at showing and not telling. The story proceeds quickly, and if you want tons of lore, you have to look in the optional encyclopedia in the menus. And, honestly, if you don't read the optional information, you might be a bit confused, because the game doesn't drown you exposition about lore, unless you choose to look into that on your own. If you want it though (and I do), you can find out a lot of interesting background information on your own time. I think this is a good thing.
-So far, it feels brisk and light, and it is not nearly as angsty or saccharine as the trailers seemed to imply.
-Also, until the systems open up and enemies get more difficult, you basically spend the first hour walking forward and then pressing circle to automatically win battles. It's frustrating because the tutorials make the system sound cool, but for a while you just cut through all the enemies like butter so you can't really use them.
- It's "Game Over" if Lightning dies in a battle. But since you can also instantly retry any battle when you lose, so it's not quite a "game over" in a conventional sense unless you make the decision not to retry. It even gives you the opportunity to go back into the menus to make adjustments, so you can't get stuck in a bad unwinnable loop. Since you are 100% cured when winning a battle, this mechanic adds tension to every random battle and makes every fight count.
-I am already totally addicted.