Paradox Interactive truly outdid themselves with this gem.
One of the top – if not the top company – for strategies, Paradox Interactive decided to take their chances, in their own production, in the 4X genre. Considering the amazing titles they have been able to produce so far (Crusader Kings, Hearts of Iron, Europa Universalis series), everybody believed that they knew what they were doing, but the challenge was still a huge one. One does not simply make a 4X game, they saying goes, but Paradox mastered the challenge and gave us Stellaris, which is probably going to establish itself as one of the best 4X titles of all times.
By adding a new concept of research ships, Paradox introduced the element of RPG into the game, but certainly not nearly as much as they have in Crusader Kings. They provided us with a vast sandbox where we could play to our own liking, but also introduced a number of systems that would ensure a more varied gameplay, as I wrote about earlier in PC Grand Strategy issue: Endgame is broken.
Having witnessed how much time and effort the good people of Paradox invest into their games, with expansions and DLC coming out frequently for years after they game has been released (see Crusader Kings 2 or Europa Universalis IV as great examples) with the purpose of expanding and improving the game with new content. I think it is a safe bet to expect the same from Paradox when it comes to Stellaris.