Fun enough for this sort of genre, but quickly descends into a grind to get coins so you can upgrade. I tend to be good at these games but couldn’t get past level 22 and 23 without some serious grinding. At that point, the AI opponent is just flying through attacks, while the human interface really shows its failings - frequently, selected attacks don’t register, hidnering the player's ability to defend and counter-attack.

I loooove this game. It is addictive. It is very entertaining. But it freezes a lot, for this reason I took off 2 stars. When I pass a level that I had previously played, where you see your score, I hit next, and it blinks, then it stays on the score screen. It won't go let me do anything. I touch the options but they don't do anything. I need to close the game to get it working again. It also should say the level number on the score screen, because if it gets frozen, you'll know which was the level you were playing.

I wrote a whole review but accidentally deleted it-If you have the win a level within 40 seconds mission, it will still give you the prize, even if you lose a game within 40 seconds.Otherwise, Great game!

When you get to challenge 30, basically it’s unbeatable. I watched a lot of ridiculous ads to get there. I maxed out everything except for the genetic upgrades on the second page. Then I had to keep leveling up in order to use the gold I now have an abundance of. So I have to beat the same levels over and over and over just to get 2% increase in speed, for instance. And I still can’t beat level 30. It would only take like 1 month of testing for the developers to figure this out.