It's fun and the progression curve is fine until you reach a certain stage, which then it becomes p2w. Because you put a lot of time and effort to get to that stage people will usually pay to progress, as to not give up and waste their effort. Or grind for months and participate in giveaways to get gems to progress faster. As a f2p, u become dependent on RNGesus, and that dude is merciless. There's videos where people spent $100s to roll a legendary pet and they still didn't get it.