Hello,
I have been active in this game for quite some time now which has provided certain characteristics such as the ability to create new battles, determining the range of ranks permitted to participate and also the number of participants in a game.
I have already paid $$$ to upgrade my tank, as it is quite impossible to get anywhere if you're only playing as a non - paying user, which is quite acceptable as many efforts and expertise are invested in creating and maintaining a game such as this one. To describe this game as a "free cost game" is only a strategy to draw people into the game and once they're hooked they'll pay to get upgrades. This is also OK because the game can only exist because of the paying participants.
What I criticize however is that you have changed the fundamental characteristics of the game, essentially creating a downgrade which is unacceptable. In order to retain the functionality of being able to create specific battles, with a set number of participants with a particular range of rank I now have to pay extra money. This is not an upgrade of the system, it's a downgrade and a considerable one. I don't like to be thrown into just any battle.
It may be OK to introduce this to non - paying free users, and it may well be easier for a new player to start off this way but to impose this downgrade on customers who have already paid an X amount of money to play the game in a certain given environment is unacceptable. If you wish to create an easy to use platform for new players that's fine, but having a rank of General I'm not really concerned about new players' problems of understanding how the game works.
It is quite OK to create new guidelines and conditions for new customers and they can choose whether to accept them or not but it is unethical to impose downgrades on existing paying customers. Admittedly I am anticipating my next higher rank which will enable me to upgrade my tank, and I will have to pay actual $$$ to do so effectively but now I'm not so sure I'll even do that. Who knows what the next downgrade will bring?
Perhaps you might consider limiting the "create battle" function to be active from a certain level upwards, which would keep things simple for newcomers but not restrict more experienced players???
My message to you is: When you make a change in the game create an UPGRADE, not a downgrade, surely not for existing customers!!!