my advice is to directly sent them to the charity and not let them spent money on your game, some people think you would use the money. There is no way to know for sure if they give money to the charity so you have to believe they did it or have them sent you screenshot of the email (with the IRS numbers removed). Then give them a key to have them download it and if they abuse it, you can remove their access.
Also no you cant tax deduct giving money to charity onto your business taxes, that only works if you did the paperwork to have your business money be sent to the charity, no other way around it.