just have a webpage form (same as used in countries that have them for pornographic sites and such) that has to be agreed to by a person over 18 to unlock proper features, otherwise you get to see the other character simply blip out of existence and your gun (and everyone else's) looks like a super soaker and shoots water or water balloon looking things, etc.
as long as it's tied to the account, you should be golden. Not sure what the big deal would be in doing something like that in the launcher.
as long as it's tied to the account, you should be golden. Not sure what the big deal would be in doing something like that in the launcher.