Let's go with the positives:
The soundtrack is amazing, one of the best even if just that login menu theme isn't enough to convince you already.
Voiceover are pretty great across languages too, although they seems to be taking different approaches for some characters across the different languages, the quality themselves is still very good.
The SFX are very satisfying and feels good when you hit things which make you want to actually shoot stuffs.
The storyline is also very good, the character involved around the story are very nicely fleshed out, even the side story has their own weights albeit some segments still fell heavily into the one-dimensional trope from time to time, but overall it's great.
The character artwork are all very nice, it has that distinct feel in coloring and artstyle that put it apart from others pretty clearly and of course are very high quality.
Now...for the rest...which are all the bads:
This is barely a game. Idle games? Sorry, you barely play the game already but most of the system lock you behind a clockwall on top of the already paywall gacha system.
The shooter gameplay is fine at best, it feels good when you hit the enemy but it is there to lock you out of content most above all. It hides the fact that the game is just an RPG but let you take the reins of the action a little bit.
You basically only have 2HP bars and you can never dodge anything so if the enemy can't die fast enough, you take damage, meaning you can't even "skill" yourself against enemy to beat them and once they mow down the debris HP bar, you're dead. Liter is especially OP because she can literally broke this system if you build her which is dumb as heck in the first place. Not to mention the "tower defense" and "time trial" mode in the story which is GUARANTEE to lock you from one of the best part of the game, the story, because there's no way an underleveled squad can power through because they can't lift their legs and dodge the bullets normally or do anything to stop the enemy advances besides shoot them untill they drop dead (they can make debris to block enemies but can't make hazards so clearly it's power sponge mentality). And no, those hazard enemies that blow up everything never appear anywhere meaningful, and the magnetic pull enemies still requires you to actually kill the enemies.
Arena is auto, go figure. Coop boss are basically big boss in story, which would require you to think a bit but that is, it's not even hard, the weakpoint is so obvious you miss it because you just lag or something and they can't even instakill you because it's normalized anyway.
Union Boss? Pray to heck you are on the same level as EVERYONE else in the guild or you do 1 damage per hit because there's no way to contribute to lower level boss once it's killed, so boss just 1 shot you while you get like 10k contribute with submachinegun.
The artwork is nice...when they are by themselves. The L2D is barely anything, the battle sprites can be silly sometimes and the fact that you have to fight on a built in vertical resolution just make the game looks broken as heck (especially the background) when you force the landscape mode (which should have been the optimal mode but it isn't so no point there). The chibis looks ugly as heck, but they are not the main stuffs in this game so it's whatever, it's not as prominent as Blue Archive so it's less obvious.
I do not mind the the gacha wall, it is something that should be there to at least support the devs going forward. But a game you barely play, locking it best aspects behind said gameplay that is below average which is also weighed down by the heavy gacha system, while that gacha system is still being weighed down by the facts that you are clockwall by the idle reward system of the game that gives out most of the progression and it just loops over and over to be a pathetic excuse of a "game".
My advice? Don't play this unless you have nothing to do, because it's literally nothing to play. If you want to sit and wait to read a visual novel, go watch a video instead, you won't have to wait, unless you like waiting and gacha to read story.
It's a very bad "GAME". It's only a game to milk the gacha, the best part aka the music and story you can just go online for them at this point.