The game started off an entertaining pass time, but the level progression is so steep, it’s enough to make me delete this game. It’s fine all the way up to like level 14, and then even after have all the newest cards fully upgraded, I had to buy my way through it with gems! I couldn’t even get close. It’d kick me back to the previous level and I’d smash it and end up back at an impossible one again. On top of that, the only way to really get any good cards is to by the special eggs with gems, and even then you get stuck with hundreds (literally) of basic cards that are obsolete; the only thing they’re good for is trading for spins, and you have to pay for that, too!
TLDR; Bottom line: unless you have hundreds of dollars to pump into it (even if it was worth it), you need hax/exploits to beat this game. That to me is extremely poor game design. And I won’t even talk about the ads.