I played the prototype a long while back, I had very high hopes for this game due to it's very unique battle system and the awesome artstyle. I finally played the full game recently and while I really liked it at first, I progressively began to like it less and less until I just had to quit.
The gameplay is a somewhat unique blend between a Turn-Based RPG, an Action RPG, a Fighting Game, and a Metroidvania. (Thought he battle system is partially taken from another game,
Valkyrie Profile [ヴァルキリープロファイル]) At first it's very fun and refreshing and it had the potential to be something truly engaging, but the battle system dragged down by the lack of depth, boiling down to simple button mashing due to the lack of certain RPG essentials like Items or spells. The game is full to the brim with party members, having about 20 of them, but only very few of them are truly ever useful, the rest being either weak or gimmicky. Because of this I always try to skip as many fights as possible, usually using overworld abiltiies to jump right past enemies.
The story is an important part of any RPG, but Indivisible's feels insanely rushed and has one of the most inconsistent tones i've ever seen in a videogame, second only to
Sonic Forces. Events that should be sad or epic are brushed off with terrible attempts at
EarthBound [Mother 2 ギーグの逆襲] style "quirky humor" that simply doesn't fit the overall tone and so many characters are introduced so fast, making it near impossible to care for them. Razmi is great though, her dialogues actually got me a few laughs.
The platforming/progression is easily the best part for me, and is honestly the only thing that would keep me playing. There's tons of well designed, challenging obstacles and discovering new areas can get very satisfying, although, gaining new abilities happens very espontaneously and feels stupidly convenient in the story. (Like a certain part where a character teaches you a new ability that you could've learned before, but it only teaches you now because gameplay demands it)
Overall, this game is painfully average and can be decently fun if you have low expectations. I'd only recommend it if you
really like indie metroidvanias, otherwise, it's pure style over substance.