Here's my take on the game:
1. A lot of the equipment seems very strong and I think it's annoying that some important ones are invisible and you can be at a big disadvantage if you don't get it so you may have to level up a lot just for missing one thing you needed.
2. Stuns last way too long. Not just that some random encounter can stun you and you lose like 3 turns and just die, but also if you use that one attack that costs like 70 and get a frost on an enemy you pretty much just win, even against bosses, as they not just lose like 3 turns they also take damage each of those turns.
3. Battles seem unbalanced. What I mean is you can pretty quickly get drained to the point of not really doing much damage. As a result, attack is like the only good stat in this game and battles are largely just do enough damage while you still can and then all the other stats are kinda useless. But I love getting drained so I really don't want to say you should get drained less, but I'd prefer if it had some sort of button mashing or other struggling little mingame where with doing well enough in it that it'd be possible to not get drained for as many levels, but doing poorly could cause you to lose even more. Also kinda makes it more realistic for those that just want to sit there and get drained more, as then they can. Although for non-boss battles the other stats matter and you can use a completely different set of equipment for them.
4. I wish we had a map or more warp points or a key item to look at to tell us where to go. Sometimes I get kinda lost and it can be annoying, but ultimately I have yet to get lost for super long in this game. But this is a very minor point as I mostly know where to go now.
5. I wish we could battle the enemies in the recollection room not just view the defeat scenes. I love doing the battle part as they use a lot of neat moves they won't use in the defeat scenes, and the battles are like the foreplay that really add a lot to the experience in my opinion. There could also be an orb to talk to to change your characters level there (reverted if you leave the recollection room) in case you need to use an appropriate level to fight some enemies.
This isn't really a suggestion but an observation. I find I run out of MP really fast in this game and use a million ethers to keep refilling it. Not sure if this is intended but it seems to me there's really not much you need to buy in this game as you can largely just find the equipment you need so there's lots of spare money to just buy more ethers with to keep refilling your MP.