Rules for publishing FREE games?

Hi!

I have multiple projects in developement, some for commercial use, but I want also to share something free with my community.
First of all, I want to give them fully working free arcade-sim (multi) and then later share with them some small games, or just demo of functions/abilities that I would like to use in later projects.

So this is range of free stuff I would like to publish, mostly on my site, also probably on moddb, since I was a modder and big part of my community is there.

Are there special rules for publishing free games or demos? Should I write an email, or contact Unreal/Epic? I do not mind, I always underline how I am happy to work on such a beasts as Unreal Engine, I just want to make sue I am doing everything all right.

I read some fragments of messages on main board, but I know these rules have changed I am bit lost about it at the moment.

If I missed tutorial or manual on that any link is appreciated, or suggestion. Thanks upfront.