Shortest answer: Sure, it's not bad unless you don't like the game mechanics.
Very long answer:
Since it's Key. It leans heavily towards Visual Novel. (it only has jp version)
If it's not for you but can get passed that, then it is for the art and music.
If you're waiting for global, then you might just try it now because I so far haven't seen any news about it getting a global one. I also kind of doubt it'll get one because of how much they have to translate if they did.
If you're a casual player, then I don't think so. Why? Because of 1 ally death = defeat. Which could be pretty punishing for some.
If you like pulling on banners a lot then, probably not. Getting currency on banner takes time like you need to progress story to get a good amount. Unless you're fine with pulling a lot by rerolling.
Which also means you're stuck with the units you'll get on the first single and 2 multis since finishing Day 7 Story is necessary for 3rd multi. So I suggest rerolling for a good team or for your waifu. Just make sure the roles and elements are not all the same.
Also worth noting that rarity A really only has 1 skill. S and SS rarity has additional skill/s but needs to be unlocked by farming mat and reaching a certain lvl on your unit. Which can also mean that Having A rarity of the unit will always be obsolette if you have an S version and it's obsolette if you have SS version. Go to my Gacha part if you want more info.
--F2p? Depends on your criteria. But mine is being able to finish content with starters which is the free SS of mc and bunch of A rarities. It's a no right now. A rarities just don't have the stats for later stages. Max lvl will also be an issue and those only have 1 skill. There is however an event. If ever a player can finish chapter 1 with starters and is able to do the event to get the S unit. Then there's a chance that it can be f2p in a distant future if more of those events show up.
all units attack in succession per turn.
3 offensive units and 3 backup units. You can switch between those units.
I can sum it up to: Break enemies shield and eliminate them.
There's auto combat and auto farm on some kind of practice arena which you can earn gp, a currency to buy chips, it has fixed stats so that's great.
Auto seems to only be good in early game because ai use heal skill like there's no tomorrow. You can turn off the auto on heal but, I don't know if the ai will ever use it when it's really needed.
There's also somekind of tower dungeon.
Then somekind of saoub style gameplay after Day 7 story where it's a side scroller where you move the character to destination while it becomes pokemon like game in a cave where the enemy can ambush you anywhere. Which means, more combat. In this mode all SP/energy you used/saved and hp/shield left will be carry over till you finish the stage. Seems like the ultimate boss stage resets this.
Decent unit pool.
Like I said, the currency takes time to get. Like you need to finish this story day number to get this amount of currency. There is log in bonus but not sure if it's perma and even if it is, it's pretty low especially if you get stuck.
Some units also have higher rarities of themselves. These versions can't be used in 1 party (putting 2 SS, S and A rarity of mc as example). Also rarities of 1 unit all have the same element so far. The only difference is A only has 1 skill. S has 2 and SS has 3. But you need to unlock the 2nd and 3rd skill which you need to farm mats and have the specific lvl to unlock it. Not to mention their starting max lvl are different. A (45) S (60) SS (90).
An A Rarity can increase max lvl through quest event with character. it gives A rarity fragment. If you max the A rarity, I think the fragment will become universal to the specific unit, like for S or SS rarity of it.
Other way is by getting exact dupe of the unit on gacha.
With all that said, so far I think all rarities of the same unit takes its highest lvl and max lvl. Like if you received an S version and you were using the A version before like lvl 10 already, then if you switch to the S version, it'll still be lvl 10 and both S and A version will have max lvl of 60.
-Unit Roles to my knowledge:
-Breaker (Breaking enemy shield faster)
-Attacker, Blaster (Can't seem to tell the 2 apart since both are just use for offensive after the shield is down and I don't use Blaster much but it's been said that it's for longer battles.)
-Healer (They can heal ally shields, but not hp and cannot bring back shield since they just always miss allies without shields so far, cannot heal shields on backup. Skill can only be used 5x)
-Debuffer (Chance to stun, def down, seal enemy skill that's all so far)
-Buffer (Increase allies atk of offensive units through skill so far)
-Defender (Attracts enemies to attack them more)
-It's also essential to know that there's color/elemental weakness in here as well. The damage feels reduced or increased by half due to it. Breaking enemies shield feels also faster if your unit is strong to it rather than using Breaker that's weak to it. This also means that you might need to lvl up different units with different elemental strengths, but that's just me.