Having a good time with this one.
Aside from the obivious srpg style that ressembles Final Fantasy Tactics in the character structure (doesn't got job change, but can equip reaction and action skills), it contains two main gameplays:
1) the 1st one is the basic structure that you see in a lot of gacha games, where you select a stage, spent energy and battle your way in this part of the campaign, along side all others gacha strucutures so far (upgrades and such);
2) The 2nd one that is intresting, as you manage a mercenary group in a small village, doing some quests and upgrading your random characters and weapons.
The point here is that at some parts you can get a early ending (still didn't get one aside the mandatory) and depending of your choices, the story takes other paths.
All in all, its a solid srpg for retro lovers with a good gameplay in battles (not all too easy, it does make you think in a lot of parts, especially at the nercenary campaign). The down side is the gacha system in the main story, as it has a low rate and requires a lot of resourse to pull...