Barotrauma is a hoot. Beater submarine being piloted by a bunch of QWOP-level controlled smack addicts.

And almost everything has varying levels of complexity. Sure, there's a pretty deep medical system with dozens of medicines of varying side effects and effectiveness for whatever ails you. Or you can just stuff yourself full of morphine (leading to the aforementioned crew of opiate addicts). You can just set the boat's ~~on board barbeque~~ nuclear reactor to automatically scale turbine output and heat levels, but either through manual management or more advanced logic circuitry you can make your boat better suited for high-intensity situations.

It does take a handful of friends to really enjoy, though. Makes it hard as an adult, but scheduling play sessions is a nice social gathering.

When you grow up, scheduling a game is THE difficult task.., for everything.., but some Saturday nights the submarine is alive with the full crew