A little bit of both, though mostly traditional.
Your enemies are on a 3x3 grid. You have special attacks that can move them around...one shoves them backwards, one to the right, one brings them forward, one pops them into the air, et cetera. The simplest and most effective use of this is knocking enemies into the same space. That way, followup attacks hit both of those enemies at once in a two-for-one strike. For example, my go-to tactic is to shove one enemy into his buddy, hit BOTH of them into a third guy, and then fry them all with powerful magic that normally only hits one target. Enemies can also hide behind shields or create status-up zones, which you should knock them away from. One character in your party can set extremely powerful traps on empty spaces, which do big damage if an enemy moves onto them (rare) or if you shove them onto it.
The grid system gets plenty of use, and it's far from being just a gimmick, but it's also doesn't really feel like a SRPG. Especially because your own characters don't move around at all. I was sort of expecting otherwise from the trailers, but I think it's the right decision and keeps the pace up.
The other aspect of the battle system is the turn cue, which works a little like Final Fantasy X. You can see which character gets each of the next ten turns in battle...and you can even switch them around a bit. Generally, you want to get your characters' turns to be consecutive in order to set up combos, even if it means changing things so that the enemies can attack you sooner.
It's really a pretty clever battle system, and I'm having a lot of fun with it. It's also quite challenging: I don't know if I'm under-leveled or what, but I'm barely scraping by in many of the standard battles, often having to use a number of healing items or spells to keep things manageable. Speaking of which, they're not random. Enemies chase you when you're in range on the map, and you can pre-hit them before the battle (a la the Mario RPG games) in order to guarantee that you get the first several strikes in the battle. And whether or not you do easily make or break you: if you try to run away and get caught from behind, the enemy group can sometimes get like seven or eight attacks before you even get started.
It's probably got the best challenge I've ever seen in a JRPG...other than TWEWY, which outright cheated
I've only lost a few battles (and they weren't even boss encounters!) but I've never felt especially safe or completely outmanned. Every battle has been engaging so far.
The story moves at a very fast pace, as well. I might even say too fast. There's hardly any down-time in the plot: you're always either on a mission, on the run, or jumping between timelines when one of them hits a brick wall. As much as I've enjoyed the 15 hours I've put in so far, I'm sort of dreading the next 20+ that I estimate will take me to the end if they keep moving the plotline(s) along this fast. Heh, I never thought I'd say that about a JRPG.
But yeah, definitely a winner so far. Already near the top of my JRPG list for sure.
