Hello, sorry for bad English, i use Google Translator.
I played your game for about 5 hours, and found a couple of shortcomings or simply moments that I personally don’t like
- Blood Screen
He is very BLOODY !!! No, I’m honest, when I come at least once, the entire screen becomes red, and I just want to hide away to something because it seems to me that they will kill me now, although I have a lot of health remains.
- Many health from dead enemy (inverted)
After the murder of the player it is necessary to spend even half the cage, it’s not quite good (I think), and it would be great if you could reduce the number of health in an overturned Player (killed)
- Few game currency
It happens that I get to win 100-200 coin, it is very small, given the fact that there are 30,000-50,000 new heroes! It would be great to increase the reward.
At this until all that! 
Thank you, sorry for my clumsy English.