I haven't finished the game yet (on D2R2), but I want to express my thoughts now as I feel like they won't change much by the time I'm done, and maybe someone can help with the issues I'm having.

Many, many issues with the gameplay. The story, too, but it seems like the writers tried to address the structural problems, and I really adore it regardless. As for the gameplay, it's hard not to get tilted after constantly being punished for things out of your control, which is especially the case when you're trying to level crap weapons. If you have a good loadout, then many of these issues are minimized, but the problem with the system is that you're forced to use bad loadouts to unlock better ones. This wouldn't be a problem if there was some mode where you could do this without having to play story missions on Easy, which feels very, very lame, but the only way you can really do that is to replay past routes. Here's a few of the more prevalent issues I've come across:
- Bullets and other small projectiles cancel your momentum and combo. When there are more than two enemies on the screen, this is stupid. Of course, with large projectiles, this makes sense, but others that come out instantly in rapid succession, have little travel time, can come from halfway across the map, are harder to see, blah blah are often impossible to avoid mid-combo. The goal is obviously to take these enemies out first, but what happens when there are 2? 4?
- Any moves that have ranged, narrow hitboxes (such as Wire Drag) are incredibly inconsistent, even if the enemy is almost stationary. Even some close-range moves don't connect when it really seems like they should. It's arguable that some moves are designed to be used only within combos rather than as combo starters, but then like, why? It's not fun. Getting 3 swarm battles into a mission and realizing your combo starter doesn't work with fast enemies is such a flaccid feeling.
- The targeting system seems to more often hinder than help. If you begin a combo and a move connects with an enemy besides the one you were targeting, you will not be able to cancel the move and will inevitably be punished, often by the targeted enemy. Also, it feels pretty lousy to be locked onto an enemy you don't want to target and have no way to manually switch, or to have the enemy you're targeting switch 0.0000001 seconds before you press the attack button.
- At higher difficulties, the game will scan your inputs and make enemies only attack once you're in startup (such that you can't bait out attacks), or dodge before your hitbox comes out. I remember one fight where a miniboss would refuse to attack without me attacking first, and when I did, throw out a super armor move that would come out before mine could connect. It took 5+ minutes to whittle its HP down with rifle or whatever terrible ranged weapon I was trying to level lol.
- There are so many silly interactions that shouldn't be in a final product. I think it's Galactic Strike where if you knock an enemy into a sloped wall (like o -> /), they will stop moving once they hit the wall, but you will keep moving along the wall, so that you may not even have a window where you can hit them. These are such minor things, but they make the game just that much less enjoyable.
And it's in almost every swarm fight that more than one of these things are an issue. That, or you have a good enough loadout to steamroll everything, which feels awesome for the first 3 battles of a mission but gets old pretty fast, especially when the enemies are more or less the same. Not to mention that there isn't much creativity with how you pick moves in each fight. I'm sure people more ingenious than me have come up with loadouts where you have some variance between combos, but the game seems to be more or less oriented towards finding a bread-and-butter chain, which maybe you can cancel early to get out of trouble but that's about it.

Also, I've been getting crashes nearly every 10 minutes, running on a modern system with updated drivers, more than enough memory, etc. Haven't heard of anyone else having the same issue, and it strangely seems to be different kinds of crashes every time. It's not so much a problem than it is just annoying, because of autosave. I'm concerned that my saves might get corrupted at some point though... I tried to submit a ticket, but the only thing it let me do was read documentation, which I am just too stupid for.

Anyway, I saw rumblings about a rerelease (FullDive?). I really do hope that the devs put effort into making it more than just a lazy collector's edition, because like I said, I do really love the plot and even many parts of the combat system and would like to play a more polished version of the game.

Nanoha best girl. I'm merging with her next week.