Game questions

[Loira]

How many servers are available in the steam version? Are they shared with other ports? Are there other ports? If yes, how do I invite my friends?
I tried to invite my friends, but it seems that it doesnt work.
Do servers reset? (Because I dislike starting all over again)
After protection ends, can you be attacked by every player even if he has a million more strenght than you?
If you are attacked by a player, do all the iddle units fight back?
On wich battles are units perma destroyed?

[Juxta]

So far there are 20 probably more to come. Go to map/ globe/ worlds there you can see which world you are on just let your friends know the world number and they can transfer there.

[PeterSvP]

There are around 20 worlds, and you can play with iOS and Android (but as far as I can tell, it looks like you can't play with Windows players)