The late Iain M. Banks wrote sci-fi novels set against the backdrop of The Culture, a sprawling futuristic civilisation where giant supercomputers did the heavy lifting. It was a vast empire, but not one ruled with an iron fist. In fact, its citizens lived very comfortable lives where they could do pretty much as they pleased. The new expansion for Stellaris, Utopia, lands alongside update 1.5, named Banks after the aforementioned author, and it's a fitting title because the focus of this expansion is on adding new options for players looking to shape the very fabric of the society that defines their empire in the stars.
Whereas the cherry on top, and maybe even the icing too (if we're going to push the analogy), is the paid content that comes with Utopia, the cake that it sits upon is very much the free 1.5 patch. We're not going to dissect what is paid and what is not, though, because the two bleed into each other after a while, layered as they are on top of several earlier post-launch patches and paid-for DLCs. Paradox has had almost a year to tighten up and remedy some of the features that felt a touch hollow at launch, and in general, we'd say that the game itself is better for the changes made.
The emphasis has very much been on adding more interesting decisions to a reasonably typical play-through. Aside from the new hive mind option (which we'll get to later), there are several new directions in which you can take your empire. For starters, when setting up a new game, instead of picking old types of government, now you're able to choose your brand of authority, and supplement that choice with new civics that give your empire a bit more personality and purpose.
To counter this renewed focus, internal factions now give you something to think about within the confines of your own empire, with various groups forming and urging you to take different paths as you expand your domain out into the farthest reaches of space. Whether it's bending to the will of alien-hating traditionalists or keeping science-loving explorers happy, there's more to factor in now than simply exercising your own will as an omnipotent leader.