5 stars: You can spend money, but you don't need to. You can get a good amount of gameplay for free before you hit a wall (I've at least unlocked the 2nd world so far, still going). It doesnt force you to watch ads, but the rewards for watching the (lots of) optional ones are decent
5 stars: It's not intrusive, it's creative, fun, challenging, and very friendly UI. Very recommended!
4 stars: The gameplay mechanics are great. Combining tower types is a great ability that sets this game apart from other tower defense apps. I haven't felt any need to purchase anything so far in order to win, so that's a win. The downside is the grammar; sometimes the English translation is so bungled that you can't understand the directions. Doesn't make much of a difference on gameplay though, just makes the game feel cheaper.
3 stars: Extremely fun at the initial stages but i don't like how the game gets harder to the point of being impossible and have to spend to win unlike Kingdom rush where you can win just by skills. The difficulty should be gradual and have the possibility to win without having to spend. This would have been the best mobile game if it wasn't for impossible level difficulty. Dissapointed.
3 stars: Initially good free to play, disappointing progression. Eventually enemies become so strong you cannot deal with them without grinding advertisements or replays or swiping your credit card and buying stronger heros/pets. Pay to win for sure. You'd have to grind fo...