Rimworld has infinite replayability due to the different biomes which change your play style, random events, random backstories of your people, and each tile in the world is different from the last.

Capture invaders, eat them, invade and steal people, harvest their organs to replace the liver of your alcoholic farmer, perform medical experiments on them for practice, sell them as slaves, or my personal favorite is to remove their legs and keep them locked in a room being fed mush until they die of old age because they set my dog on fire. There are numerous other wonderfully horrible game mechanics that make this game great.

Best war crime simulator you can find.

Worth the buy at full price!