So, to sum it all up.
At first, I couldn't even get the game to start.
When I finally did, i realized that the mod launcher is broken and it's completely screwed up when it comes to mod loading order. Which is a bit of an issue if you use those big ones, like NSC or Planetary Diversity.
Had to enable every single mod I used before manually, which is made ten times more annoying than it should be, because the launcher is not even in bloody alphabetical order.
The game now loads. Hooray. Except not really, because it crashes when I try to start a game.
So I reverted to previous version - but here's another issue. Because new launcher reads mods differently (they're no longer just zip files in steam workshop folder), the updated ones no longer work on the older version.
So in conclusion - can't play the old version, can't play the new version. Job well done, Paradox, your game certainly has been "updated"
fml...