Originally posted by The Father ☯:

I just don't want a Space Engineers repeat where it's a nice put together world but not really fun without other people and the enemy is lackluster

Heh, well, it's nothing like Space Engineers (thank Odin!) ;)
It can still be a lot of fun solo and it can be fun to play with friends. Playing with friends will definitely make it an easier game too and make for a little less grind.
It really isn't a very hard game to play and there's more challenge to actually locate some of the bosses than killing them, which only requires good thought & preparation.
The thing about this game that will keep you playing IMO is the beauty of it and the freedom you have to build ;)