If you've tried dwarf fortress but are overwhelmed by the UI and options available, this game has got you covered. It's easy to learn and the UI has a clean, easy to use design. The DLC expand on the game in mayor ways as well so when you get bored of the basegame, there's options. Not to mention the incredible mods made and updated frequently.

My favourite part of this game is probably that there is ALWAYS a way out of any situation as long as you're willing to forgo compassion and morals (but please don't take that as RL advice). No food? Eat the weakest colonist. Prisoners getting rowdy? Not without legs they're not. Raids getting overwhelming? Have you considered simply putting them in an industrial sized oven?

pros, being inside your sub

cons, the outside constantly trying to get in

honestly this game is fantastic, the bots are a bit dumb but manageable so singleplayer is very viable, however it's by far better with some friends to play with. The submarine editor is hard to figure out but once you do, the game becomes infinitely better, being able to play on your own custom vessel as well as those made by fellow players.