Great game, lots of choices on playstyle, "jobs" and world generation.
Mods definitely improve the game by a huge margin.
Best mod I ever added to the game was the Calamity mod.
Overall, vanilla or modded, this is an amazing game that you won't burn through in just a few hours.
It will take days of REAL LIFE TIME to complete a world, and even then you won't be done playing.