I've started about 3 weeks ago, already got into 2 events. I have 3 or 4 Super Rare companions and can score over 1M points regularly. I'm finding it very fun.
The flying gameplay was shit, but after the last update it's my favorite one. My Tails is over level 40 already.
How is Chain Chronicles? Does it have catgirls?
Chain Chronicles has all kinds of girls! The characters are all kinds of cool;
What stands out is that each character has it's own substory and keeps appearing in some sidequests, events or the main story, they're not just in the game as cards. Furthermore they all have their own models and special abilities. Pheona here gives a 10% attack buff and 5% defence buff if she's in your party but she's got weak base stats. She has a special screenwide attack but requires 3 mana. Melvina next to her has a 1 mana healing move that also cures poison and is better than Pheona on her base stats. Toka and Haruaki are needed to unlock each other's quests but they differ too, Toka has a pre-wave healing ability and Haruaki does double damage to Ogres in the game (There are like 5 different types of enemies in the game.)
Basically SEGA put a lot of thought into this game and that's why it's a massive success.