This game is nearly perfect refined version of the genre. If you like city building and management games like Dwarf Fortress, Gnomoria, or SimCity. You will love Rimworld, and play it a ton. The setting is unique for this type of game and it really works well. Your trying to survive and get off a crummy planet. The UI solves many of the problems with Dwarf Fortress. It has a great tutorial system to help you learn the game as you go. It is much more polished than Gnomoria and it fleshed out the mechanics.
The games core game play loop is fun, progresses, and finally ends in a satisfying way. There are set backs, chaos, and tragedy. I have 80 hours in the first week of play. I have nearly finished my first play through (Pheobe, Medium, Temp Forest), and am already planning out my next play through (Cassandra, Brutal, Arid).
The mechanics are funny, and entertaining. I have great memories of the first time I wiped out and enemy camp, and nearly lost several of my best shooters, and brought them back from near death with glitter world meds, and a last second save by the doc. I halariously dropped a anti-grain shell on the next camp, 12 dead and rest fleed immediately. Shot three more as they ran. I love wounding enemys, capturing them, patching them back up and getting more colonist.
This game is a masterpiece.