Need clarity about game with donations

I am planning to distribute my game for pc for free. Only revenue I will be getting from my game is by donations received from the end user if they press donate button which is available in game menu screen itself. I assure you that I will pay 5% royality fee for revenue generated through donations. But I want assurance that is it ok for you to release my game for free or it is mandatory to release my game with payment option. Please reply to my doubt.
I look forward to hearing from you

Pure donations - that are not tied to game access or other in-game benefit - are not subject to a royalty. You are not obligated to release a game which requires payment.