The game suffers from several abuse vectors one is people will use multiple accounts to bully and farm other players,customer service is non-responsive to this, and there are all sort of exploits as well that players can and will abuse without any ramifications.
The developers in their infinite wisdom supposedly made matchmaking changes, this has resulted in players that can be five hundred levels above you being able to hit down, theres nothing about that one could call good matchmaking or good game balance. It just becomes a more obvious pay to win app.
If you do download this game I recommend you dont spend any money till the developers can show proper customer service and support for their app and mole net proper game balance unless you are a fan of pay to win.