Is it obligatory to return the price of pirated games to their owners, and what should I do if I am unaware of their number and the companies that produced them?

Downloading games or programs without the owners' permission is an infringement upon their rights, and the high price does not make it permissible. You can absolve yourself of what you have infringed upon by paying the owners the value of the benefits you have deprived them of, estimated by experts, or by diligently estimating and paying it if that is difficult. If it is impossible to pay the amount to the owning companies, then donating it to the poor and needy with the intention of absolution is sufficient.